250-RICR-150-05-3
250-RICR-150-05-3. Groundwater Quality Rules (version Amendment, 07/26/2010 to 01/09/2019)
STATE OF RHODE ISLAND AND PROVIDENCE PLANTATIONS
DEPARTMENT OF ENVIRONMENTAL MANAGEMENT
Office of Water Resources
GROUNDWATER QUALITY RULES
June 2010
AUTHORITY: These Rules are adopted in accordance with Chapter 42-35 pursuant to Chapters 46-12, 46-13.1, 23-
18.9, 23-19.1, 42-17.6 and 42-17.1 of the Rhode Island General Laws of 1956, as amended.
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Groundwater Quality Rules, June 2010
STATE OF RHODE ISLAND AND PROVIDENCE PLANTATIONS
DEPARTMENT OF ENVIRONMENTAL MANAGEMENT
GROUNDWATER QUALITY RULES
TABLE OF CONTENTS
RULE 1. PURPOSE ................................................................................................................................................................... 1
RULE 2. LEGAL AUTHORITY............................................................................................................................................... 1
RULE 3. LIBERAL APPLICATION..........................................................................................................................................1
RULE 4. SEVERABILITY........................................................................................................................................................ 1
RULE 5. APPLICABILITY....................................................................................................................................................... 1
RULE 6. FINDINGS.................................................................................................................................................................. 2
RULE 7. DEFINITIONS............................................................................................................................................................ 4
RULE 8. PROHIBITIONS AND OTHER GENERAL REQUIREMENTS........................................................................... 9
RULE 9. GROUNDWATER CLASSIFICATION................................................................................................................. 10
RULE 10. MODIFICATION OF GROUNDWATER CLASSIFICATION ………………………………………………...12
RULE 11. GROUNDWATER QUALITY STANDARDS AND PREVENTIVE
ACTION LIMITS......................................................................................................................................................................... 15
RULE 12. DETERMINATION OF COMPLIANCE WITH GROUNDWATER QUALITY
STANDARDS AND PREVENTIVE ACTION LIMITS ........................................................................................................... 20
RULE 13. POINTS OF COMPLIANCE.....................................................................................................................................21
RULE 14. NOTIFICATION TO DEM OF VIOLATIONS OF PREVENTIVE ACTION
LIMITS AND GROUNDWATER QUALITY STANDARDS...................................................................................................23
RULE 15. FACILITY OWNER OR OPERATOR RESPONSES TO VIOLATIONS
OF PREVENTIVE ACTION LIMITS AND GROUNDWATER QUALITY STANDARDS………………………………25
RULE 16. GROUNDWATER REMEDIATION....................................................................................................................... 29
Groundwater Quality Rules, June 2010
GROUNDWATER QUALITY RULES
TABLE OF CONTENTS
(Continued)
RULE 17. GROUNDWATER QUALITY CERTIFICATION..................................................................................................31
RULE 18. WELLHEAD PROTECTION................................................................................................................................... 32
RULE 19. VARIANCES..............................................................................................................................................................35
RULE 20. ENFORCEMENT.......................................................................................................................................................36
RULE 21. APPEALS ...................................................................................................................................................................36
RULE 22. SUPERSEDED REGULATIONS..............................................................................................................................36
RULE 23. PENALTIES .............................................................................................................................................................. 36
Appendix 1. Construction Standards and Abandonment Procedures for Monitoring Wells, Piezometers and Other Subsurface
Borings…………………. .............................................................................................................................................................37
Appendix 2. Groundwater Classification Map (8.5" x 11") ........................................................................................................44
Appendix 3. Map of Groundwater Reservoirs and the Critical Portions of Their Recharge Areas (8.5" x 11") .......................46
Appendix 4. Wellhead Protection Area Map (8.5” x 11”) ………………………………………………………………… 48
Appendix 5. Wellhead Protection Area Delineation Methodology…………………………………….……………………50
RULE 24. EFFECTIVE DATE....................................................................................................................................................54
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STATE OF RHODE ISLAND AND PROVIDENCE PLANTATIONS
DEPARTMENT OF ENVIRONMENTAL MANAGEMENT
Office of Water Resources
GROUNDWATER QUALITY RULES
RULE 1. PURPOSE
It is the purpose of these Rules to protect and restore the quality of the state's groundwater resources for use as drinking water
and other beneficial uses, and to assure protection of the public health and welfare and the environment.
RULE 2. LEGAL AUTHORITY
These Rules are promulgated pursuant to the requirements and provisions of Chapter 46-12, Water Pollution; Chapter 46-
13.1, Groundwater Protection; Chapter 23-18.9, Refuse Disposal; Chapter 23-19.1, Hazardous Waste Management Act:
Chapter 42-17.1, Environmental Management; Chapter 42-17.6, Administrative Penalties for Environmental Violations; in
accordance with Chapter 42-35, Administrative Procedures, of the Rhode Island General Laws of 1956, as amended.
RULE 3. LIBERAL APPLICATION
The terms and provisions of these Rules shall be liberally construed to allow the Department to effectuate the purposes of
state and federal laws, goals, and policies.
RULE 4. SEVERABILITY
If any provision of these Rules, or the application thereof to any person or circumstances, is held invalid by a court of
competent jurisdiction, the validity of the remainder of the Rules shall not be affected thereby.
RULE 5. APPLICABILITY
5.1 These Rules apply to all of the groundwater of the state.
5.2 Persons subject to these Rules may also be subject to other regulations of the Department and may also be subject to
federal regulations. Obligations of facility owners and facility operators hereunder shall be joint and several.
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5.3 These Rules shall be construed in harmony with other Department regulations and the regulations of federal agencies.
Nothing in these Rules shall affect the Director's power and duty to issue or require any form of groundwater monitoring,
groundwater remediation, enforcement action or other action pursuant to any other regulatory program administered or
enforced by the Director.
5.4 Monitoring Wells and Other Subsurface Borings: Monitoring wells installed pursuant to these Rules shall be in
compliance with the construction standards in Appendix 1. The monitoring well abandonment procedures in Appendix 1
shall apply to all monitoring wells and other subsurface borings, including piezometers.
5.5 The Director may require any facility owner or operator subject to these Rules to provide any information deemed
necessary in order to determine compliance with these Rules. Failure to disclose such information shall be cause for initiating
appropriate enforcement action and shall constitute valid cause for denial of any Departmental approvals under these Rules or
the suspension of any approval issued hereunder.
5.6 Nothing in these Rules shall affect the Director's power and duty to issue an immediate compliance order or take any
other action pursuant to the General Laws of Rhode Island, 1956, as amended.
RULE 6. FINDINGS
The legislative findings set forth in the Rhode Island Groundwater Protection Act of 1985, section 46-13.1-2 of the General
Laws of Rhode Island, 1956, as amended and which are repeated below in Rule 6.1 and the additional findings of the
Department set forth in Rule 6.2 are made a basis for these Rules.
6.1 Legislative Findings
6.1.1 Water is vital to life and comprises an invaluable natural resource which is not to be abused by any segment of the
state's population or its economy. It is the policy of the state to restore, enhance, and maintain the chemical, physical,
and biological integrity of its waters, to protect public health, to safeguard fish and aquatic life and scenic and ecological
values, and to enhance the domestic, municipal, recreational, industrial, and other uses of water.
6.1.2 The groundwaters of the state are a critical renewable resource which must be protected to insure the availability
of safe and potable drinking water for present and future needs.
6.1.3 It is a paramount policy of the state to protect the purity of present and future drinking water supplies by
protecting aquifers, recharge areas, and watersheds.
6.1.4 It is the policy of the state to restore and maintain the quality of groundwater to a quality consistent with its use
for drinking water supplies and other designated beneficial uses without treatment as feasible. All groundwaters of the
state shall be restored to the extent practicable to a quality consistent with this policy.
6.1.5 It is the policy of the state not to permit the introduction of pollutants into the groundwaters of the state in
concentrations which are known to be toxic, carcinogenic, mutagenic, or teratogenic. To the maximum extent practical,
efforts shall be made to require the removal of those pollutants from discharges where such discharges are shown to
have already occurred.
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6.1.6 Existing and potential sources of groundwater shall be maintained and protected. Where existing quality is
inadequate to support certain uses, the quality shall be upgraded if feasible to protect the present and potential uses of
the resource.
6.1.7 The groundwaters of the state are to be protected for use as agricultural, industrial, and potable water supplies, and
other reasonable uses, and as a supplement to surface waters for recreation, wildlife, fish and other aquatic life,
agriculture, industry, and potable water supply.
6.1.8 Discharges to groundwater which subsequently discharge into surface waters and which would cause a
contravention of surface water quality or standards shall not be permitted.
6.1.9 No degradation of the state's groundwaters shall be permitted unless the state chooses to allow lower water quality
as a result of the essential, desirable and justifiable economic, commercial, industrial, or social development.
6.2 Administrative Findings
6.2.1 Approximately 25% of the population of Rhode Island depends on groundwater for its drinking water supply, and
approximately 27 million gallons of groundwater are used every day in Rhode Island.
6.2.2 Approximately two-thirds of the cities and towns in Rhode Island depend on groundwater for all or a significant
portion of their public and private drinking water supply needs.
6.2.3 Four sole source aquifers (Block Island, Pawcatuck Basin, Hunt-Annaquatucket-Pettaquamscutt, and Conanicut
Island (Jamestown) Aquifers) have been designated in Rhode Island by the United States Environmental Protection
Agency in accordance with Section 1424(e) of the federal Safe Drinking Water Act of 1974.
6.2.4 Surface water and groundwater are interconnected parts of the hydrologic cycle. During dry periods between
rainfall and snowmelt, surface water in streams and rivers is derived almost entirely from groundwater discharge.
Therefore, protection of groundwater quality is necessary to maintain surface water quality.
6.2.5 The groundwater resources of the state with the highest potential yield are located in glacial deposits of stratified
drift which underlie about one-third of the state. These groundwater resources are vulnerable to pollution due to the
relatively high water table, high permeability, and the absence of a confining subsurface layer that would inhibit
movement of pollutants to groundwater.
6.2.6 Most private drinking water supplies and many small public water systems obtain water from fractured bedrock
aquifers. Groundwater pollution in bedrock is extremely difficult to monitor and remediate.
6.2.7 Groundwater pollution continues to threaten public and private drinking water supplies. A significant number of
public and private wells in Rhode Island have had pollutants in concentrations that have adversely impacted their use.
6.2.8 Groundwater pollution must be prevented wherever possible because of the actual and potential adverse effects on
public health and the environment and due to the technical difficulties and economic costs involved in groundwater
remediation.
6.2.9 Certain activities that represent a potential threat to groundwater quality are not appropriate in particular areas
because of the sensitivity and value to the state of the underlying groundwater resource.
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RULE 7. DEFINITIONS
"Annular space seal" means the material placed above the top of the filter pack or the filter pack seal up to the ground
surface seal and between the well casing and the adjacent formation.
"Aquifer" means a geologic formation, group of formations, or part of a formation that contains sufficient saturated,
permeable material to yield significant quantities of water to wells and springs.
"Bedrock" means solid rock, commonly called ledge, which forms the earth's crust, including fracture zones within said
rock.
"Best management practices" means schedules of activities, prohibitions of practices, maintenance procedures, and other
management practices designed to prevent or reduce the degradation of the state's groundwater to the maximum extent
possible.
"Community water supply well" means a well that serves a community water system.
"Community water system" means a public water system which serves at least 15 service connections used by year-round
residents or regularly serves at least 25 year-round residents.
"Degradation" means a deterioration or decline in groundwater quality.
"Department" means the Rhode Island Department of Environmental Management or its successor.
“Direct push well” means a well that is advanced into the subsurface without drilling.
"Director" means the director of the Rhode Island Department of Environmental Management or the Director's designee.
"Discharge to groundwater" means the intentional, negligent, accidental, or other release of any pollutant onto the land
surface in a location where it may enter the groundwater of the state, or such release of any pollutant beneath the land surface.
"Effluent" means liquid that is discharged from a facility.
"Emergency response" means any action undertaken immediately following the discovery of a release in order to
completely or partially contain, clean up or treat the released material to prevent an immediate or substantial threat or risk of
acute or chronic adverse effect on human health or to prevent an immediate or substantial significant adverse impact to the
environment.
"Facility" means any parcel of real estate or a contiguous series or parcels of real estate together with any and all structures,
facility components, improvements, fixtures and other appurtenances located therein or thereon which constitutes a distinct
geographic unit.
"Filter pack" means the sand, gravel, or both placed in direct contact with the well screen.
"Filter pack seal" means the sealing material placed in the annular space above the filter pack and below the annular space
seal to prevent the migration of annular space sealant into the filter pack.
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"Groundwater" means water found underground which completely fills the open spaces between particles of sediment and
within rock formations.
"Groundwater quality classification" means the categorization of groundwater as usable for particular purposes on the
basis of its physical, chemical, and hydrogeologic characteristics; also, the particular class (GAA, GA, GB, or GC) assigned
to a particular volume of groundwater within specific geographic boundaries.
"Groundwater quality standards" means concentrations of specific chemical, biological, and radiological constituents and
narrative statements which describe the quality of groundwater which shall be met in a particular groundwater quality
classification.
"Groundwater recharge" means the process of adding water to the zone of saturation; or the quantity of water added to the
zone of saturation.
"Groundwater reservoirs" means those stratified drift deposits having a saturated thickness greater than or equal to 40 feet
and a transmissivity greater than or equal to 4000 feet squared per day which have been designated by the Director to be
potentially significant sources of water.
“Grout” means a low permeability material consisting of bentonite, neat cement or a neat cement-bentonite mixture.
"Hazardous material" means any material or combination or mixture of materials containing any hazardous substance in an
amount and concentration such that when discharged to groundwater will or may reasonably be expected to cause acute or
chronic adverse effects on human health or the environment. Hazardous material shall also include any material that contains
a hazardous waste.
"Hazardous substance" means any substance designated as such pursuant to 40 CFR 300.5.
"Hazardous waste" means hazardous waste as defined in the Rhode Island Department of Environmental Management
“Rules and Regulations for Hazardous Waste Management”.
"Hydraulic conductivity" means a measure of the ability of an aquifer to transmit a fluid; it is expressed as the volume of
water at the existing kinematic viscosity that will move in a unit time under a unit hydraulic gradient through a unit area
measured at right angles to the direction of flow.
"Licensed solid waste landfill" means any solid waste disposal facility consisting in whole or in part of a landfill, which
facility is operating pursuant to a valid department license issued pursuant to a final action of the Director as to which all
applicable appeals periods have expired.
"Monitoring well" means a well that is specifically located, designed, constructed, and emplaced to sample groundwater
quality; the monitoring well may also be used to measure water table elevations.
"Monitoring well abandonment" means to remove a monitoring well from service in such a manner that vertical movement
of water within the well bore and within the annular space surrounding the well casing is effectively and permanently
prevented.
“Neat cement” means a mixture of Portland cement (ASTM C-150 standard) and water in the proportion of 5 to 6 gallons of
clean water per bag (94 pounds or one cubic foot).
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“Neat cement-bentonite mixture” means a mixture of 6 to 7 gallons of water per 94 pound bag of Portland cement with up
to 10% (by dry weight of cement) of unaltered dry bentonite powder added after the initial mixing of cement and water.
“Non-aqueous phase liquid” means any pollutant that is present as a separate phase liquid, including, but not limited to
sheens.
"Non-community water supply well" means a well that serves a non-community water system.
"Non-community water system" means a public water system that is not a community water system.
"Non-transient non-community water supply well" means a well that serves a non-transient non-community water
system.
"Non-transient non-community water system" means a non-community water system that regularly services at least 25 of
the same persons over six months per year.
"Onsite Wastewater Treatment System" means any system of piping, tanks, dispersal areas, alternative toilets or other
facilities designed to function as a unit to convey, store, treat or disperse wastewater by means other than discharge into a
public sewer system.
"Operator" means any person or persons having control or having legal responsibility for operating or maintaining any
facility, which is subject to these Rules.
"Owner" means any person who holds exclusive or joint title to, or lawful possession of real or personal property, which is
subject to these Rules.
"Person" means an individual, trust, firm, joint stock company, corporation (including a quasi-governmental corporation),
partnership, association, syndicate, municipality, municipal or state agency, fire district, club, non-profit agency, or any
subdivision, commission, department, bureau, agency or department of state or federal government (including quasi-
governmental corporation), or any interstate or international body, or any agent or employee thereof.
“Petroleum” means crude oil, any fraction of crude oil, any substance refined or derived from crude oil, or any mixture
thereof, including, but not limited to, gasoline, petroleum solvents, kerosene, aviation fuels, diesel oils, fuel oils, waste oils,
lubricants, tar and asphalt.
"Piezometer" means a well with a short screen that allows measurement of the water level at a particular depth in the
aquifer.
"Pollutant" means any material or effluent which may alter the chemical, physical, biological, or radiological characteristics
and/or integrity of water, including but not limited to, dredged spoil, solid waste, incinerator residue, sewage, garbage,
sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded
equipment, cellar dirt or industrial, municipal, agricultural, or other waste or material, petroleum or petroleum products,
including but not limited to oil.
"Pollutant discharge zone" means a departmentally designated, three-dimensional zone within which the pollutant
concentrations resulting from an active discharge to groundwater are allowed to be greater than the groundwater quality
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standards.
"Pollution" means the man-made or man-induced alteration of the chemical, physical, biological, and radiological integrity
of water.
"Preventive action limit" means a concentration of a substance that is equal to 50% of the numerical groundwater quality
standard.
"Private well" means a well established for the purpose of meeting all or part of a person's potable water needs provided said
well does not supply a public water system.
"Public water system" means a system for the provision to the public of piped water for human consumption, provided such
a system has at least 15 service connections or regularly serves an average of at least 25 individuals daily at least 60 days out
of the year; and shall include all sources and facilities involved in collecting, treating, storing, and distributing the water.
"Public well" means a well that serves a public water system.
"Recharge area" means the land surface from which water is added to the zone of saturation. The recharge area for a
particular well or aquifer, for instance, is that land surface from which water moves to the well or aquifer or may move to the
well or aquifer under certain hydraulic conditions.
"Refined wellhead protection area" means a wellhead protection area approved and designated by the Director based upon
a delineation submitted to the Director or prepared by the Director using more complex methods or additional data than that
used in the Director's initial delineation.
"Release" means any spilling, leaking, pumping, pouring, emitting, emptying, injecting, escaping, leaching, dumping, or
disposing of any pollutant onto or below the land surface. For purposes of these Rules, release also includes any storage,
disposal, or abandonment of any substance or material in a manner that presents a substantial threat of release as herein
defined.
"Remediation" means prevention and control of pollutant migration to, within, or from the groundwater or the removal of a
pollutant from the groundwater.
"Residual zone" means a departmentally designated, three-dimensional zone within which the pollutant concentrations
remaining in the groundwater after remediation activities are allowed to be greater than the groundwater quality standards.
"Sanitary sewage" means any human or animal excremental liquid or substance, any putrescible animal or vegetable matter
or any garbage and filth, including, but not limited to, any gray water or black water discharged from toilets, washing
machines, sinks and dishwashers as well as the content of septic tanks, cesspools, or privies.
"Saturated thickness" means the thickness of an aquifer measured from the water table to an essentially impermeable
boundary; such boundary is typically taken to be the top of the bedrock surface.
"Saturated zone" means the subsurface zone in which all open spaces are filled with water.
"Sludge" means residue, whether partially solid or solid, treated or untreated, resulting from the treatment of sewage,
including, without limitation, such residues from the cleaning of sewers, by processes, such as settling, flotation, filtration and
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centrifugation, and shall not meet the criteria for a hazardous waste as found in the Rhode Island Department of
Environmental Management “Rules and Regulations for Hazardous Waste Management”.
"Sole source aquifer" means an aquifer designated by the United States Environmental Protection Agency as the sole or
principal source of drinking water for the area above the aquifer and including those lands where the population served by the
aquifer live; that is, an aquifer which is needed to supply 50% or more of the drinking water for that area and for which there
are no reasonably available alternative sources should the aquifer become polluted.
"Solid waste" means solid waste as defined in the Rhode Island Department of Environmental Management “Solid Waste
Regulations No.1–No.8”; and which shall include garbage, refuse and other discarded solid materials generated by
residential, institutional, commercial, industrial and agricultural sources but does not include solids or dissolved materials in
domestic sewage or sewage sludge, nor does it include hazardous waste. Solid waste shall also include non-hazardous liquid,
semi-solid, and containerized gaseous waste.
"Static water table" means the water table under natural, non-pumping conditions.
"Stratified drift" means predominantly sorted sediments deposited in layers by meltwater from a glacier.
"Till" means predominantly unsorted, unstratified sediments deposited directly by a glacier.
“Transient non-community water supply well” means a well that serves a transient non-community water system.
“Transient non-community water system” means a non-community water system that does not regularly serve at least 25
of the same persons over 6 months per year.
"Transmissivity" means a measure of the ability of an aquifer to transmit a fluid through a unit volume of the aquifer. It can
be quantified as the hydraulic conductivity multiplied by the saturated thickness.
"Unconfined aquifer" means an aquifer that is not under pressure beneath a relatively impermeable layer. The groundwater
in an unconfined aquifer is under atmospheric pressure, and its upper surface is the water table.
"Underground storage tank" means any one or combination of tanks (including underground pipes connected thereto)
which is used to contain an accumulation of petroleum product or hazardous material, and the volume of which (including the
volume of the underground pipes connected thereto) is 10 percent or more beneath the surface of the ground.
“Watercourse” means any river, stream, brook, pond, lake, swamp, marsh, bog, fen, wet meadow, area subject to storm
flowage, or any other standing or flowing body of water, including such watercourses that may be affected by the tides.
"Water table" means the upper surface of the saturated zone in an unconfined aquifer.
"Well" means a bored, drilled, or driven shaft or a dug hole, with a depth that is greater than its largest surface dimension,
through which groundwater flows, has flowed, or may flow under natural or induced pressure.
"Wellhead protection area" means the critical portion of a three-dimensional zone surrounding a public well or wellfield
through which water will move toward and reach such well or wellfield as designated by the Director.
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RULE 8. PROHIBITIONS AND OTHER GENERAL REQUIREMENTS
8.1 Groundwater shall be maintained at a quality consistent with its classification. No person shall take actions that violate
or cause to violate the standards established in these Rules.
8.2 No person shall cause or allow a discharge of any pollutant to groundwater without the approval of the Director pursuant
to these and other Department rules and regulations.
8.3 No person shall operate or maintain a facility in a manner that may result in a discharge of any pollutant to groundwater
without the approval of the Director.
8.4 The establishment of new solid waste landfills is prohibited in areas where the groundwater is classified GAA or within
a wellhead protection area designated in accordance with Rule 18.
8.5 The establishment of new facilities that are required to be permitted as treatment, storage or disposal facilities or require
Letters of Authorization for temporary storage and/or transfer areas of hazardous waste pursuant to the Rhode Island “Rules
and Regulations for Hazardous Waste Management” is prohibited within the areas listed below in 8.5.1 – 8.5.3. This
prohibition does not apply to the following: generators of hazardous waste as defined in the Rhode Island “Rules and
Regulations for Hazardous Waste Management”; emergency permits for the treatment of hazardous waste under section 7 of
the Rhode Island “Rules and Regulations for Hazardous Waste Management”; and treatment of hazardous waste as part of an
emergency permit or a remedial action approved pursuant to the Rhode Island “Rules and Regulations for the Investigation
and Remediation of Hazardous Material Releases”.
8.5.1 Where the groundwater is classified GAA;
8.5.2 Within a wellhead protection area designated in accordance with Rule 18; and
8.5.3 Within areas where the groundwater is classified GA where public water is not available to all surrounding
properties.
8.6 The establishment of new facilities or new locations for the temporary or permanent storage of road salt or salt/sand
mixtures is prohibited where the groundwater is classified GAA or GA unless the storage meets the following conditions:
8.6.1 Within a weatherproof structure if the pile is larger than 100 cubic yards, otherwise a secured, durable, waterproof
covering is sufficient;
8.6.2 On an impermeable base; and
8.6.3 Runoff from the operational area around the salt or salt/sand storage is controlled by best management practices.
8.7 At locations where road salt or salt/sand mixtures have been stored over groundwater classified GAA or GA prior to
April 17, 2005, any future storage of road salt or salt/sand mixtures at these locations must, at minimum be covered with a
secured, durable, waterproof cover to protect the salt from precipitation.
8.8 No person shall install underground storage tanks within the wellhead protection area of community water supply wells
designated in accordance with Rule 18. However, underground storage tanks that have been registered prior to October 22,
2002 and have not been abandoned or removed from the ground for more than 180 days shall be permitted to be replaced
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with a tank(s) of equivalent size or less, and substance stored in accordance with the provisions of the Rhode Island “Rules
and Regulations for Underground Storage Facilities Used for Petroleum Products and Hazardous Materials”.
RULE 9. GROUNDWATER CLASSIFICATION
(See Appendix 2 for a small scale Groundwater Classification Map.)
9.1 Definitions: The Director shall classify the groundwater resources of Rhode Island using the four classes established in
Chapter 46-13.1 of the General Laws of Rhode Island, 1956, as amended and which are further defined below:
9.1.1
Groundwater classified GAA shall be those groundwater resources which the Director has designated to be
suitable for public drinking water use without treatment and which are located within the areas described in A-C below.
(A) Groundwater reservoirs and portions of their recharge areas as delineated by the Department (see Appendix 3),
pursuant to the method described in Policies and Procedures for Mapping Recharge Areas to Groundwater
Reservoirs for GAA Classification, Rhode Island Department of Environmental Management, March, 1991;
(B) Wellhead protection areas for community water supply wells delineated in accordance with Rule 18.
Wellhead protection areas for community water supply wells will by definition be considered reclassified to GAA
at the time of approval of the community water supply well by the Rhode Island Department of Health.
(C) Groundwater dependent areas that are physically isolated from reasonable alternative water supplies and
where the existing groundwater supply warrants the highest level of protection.
9.1.2 Groundwater classified GA shall be those groundwater resources which the Director has designated to be suitable
for public or private drinking water use without treatment and which are not described in Rule 9.1.1(A)-(C).
9.1.3 Groundwater classified GB shall be those groundwater resources designated by the Director which may not be
suitable for public or private drinking water use without treatment due to known or presumed degradation.
Groundwater located beneath the following areas may be classified GB:
(A) Highly urbanized areas of the state with dense concentrations of historic industrial and commercial activity,
wherein a public water supply is readily available;
(B) The permanent waste disposal area as approved by the Director in accordance with the Rhode Island “Rules
and Regulations for the Investigation and Remediation of Hazardous Material Releases” at the sites of
historically permitted or approved inactive landfills and inactive land disposal sites for solid waste, hazardous
waste, or sewage sludge;
(C) Active sites that are permitted for the land disposal of sewage sludge, unless such disposal site is associated
with a licensed solid waste landfill; or
(D) The area immediately surrounding the area classified GB in accordance with Rule 9.1.3(B) and (C) which the
Director has determined is not suitable for public or private drinking water use or the area immediately surrounding
the area classified GC in accordance with Rule 9.1.4, which the Director has determined is not suitable for public or
private drinking water use..
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9.1.4 Groundwater may be classified GC in those areas which, because of present or past land use or hydrogeological
conditions, the Director has determined to be more suitable for certain waste disposal practices than for development as
a drinking water supply.
(A) Groundwater located beneath the following areas may be classified GC:
(i) At licensed solid waste landfills:
(a) The currently permitted area for waste disposal as established in a valid operating license issued by
the Department, including a license issued pursuant to a court order; and
(b) Areas surrounding the permitted area for waste disposal that the Director determines are potentially
suitable for waste disposal based on the hydrogeologic environment, groundwater quality, groundwater
use off-site, and surrounding surface water quality and use;
(ii) Areas that have been reclassified pursuant to Rule 10.7 for solid waste landfills and facilities for the
disposal of hazardous waste.
(B) At the point in time when a license for a solid waste landfill or facility for the disposal of hazardous waste has
lapsed or the facility is no longer being operated, then by definition the site shall be considered reclassified to GB,
unless the Director determines that the GC classification is appropriate for the site.
9.2 Classification Boundary Disputes: In the event that the boundaries of the groundwater classification areas shown on
groundwater classification maps produced by the Department are in dispute, the burden of proof shall be on the person
disputing the boundary locations as shown on such map to show, pursuant to Rule 10, that the boundary locations are
incorrect. In determining the accuracy of the Director's delineations, the regional hydrogeologic conditions beyond the
boundaries of the specific site in question and the seasonal fluctuations in the water table shall be considered.
9.3 Classification Maps: The Director shall prepare and adopt, simultaneously with the adoption of these Rules,
groundwater classification maps, which designate groundwater classification pursuant to these Rules. Said groundwater
classification maps shall be at a scale of 1:24000, and such maps shall be on file for review at the Rhode Island Department of
Environmental Management, 235 Promenade Street, Providence, RI 02908. Smaller scale, statewide maps may be made
available from the Department at the above address, and groundwater classifications may be viewed on the DEM website at
www.dem.ri.gov
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RULE 10. MODIFICATION OF GROUNDWATER CLASSIFICATION
10.1 Groundwater Classification Changes by the Director: The Director may from time to time propose changes in the
groundwater classifications as more information becomes available. The changes shall be delineated in a manner consistent
with Rule 9. At such time that the Director proposes a change in the groundwater classification, the Director shall initiate
rule-making procedures.
10.2 Request for Modification of Groundwater Classification
10.2.1 Any person who may be substantially and specifically affected may petition the Director to modify the
classification assigned to particular groundwaters of the state.
10.2.1 The petitioner for a reclassification shall specify the precise boundary in question and prove by clear, convincing
and scientifically valid evidence that a reclassification is consistent with Rules 10.4, 10.5, 10.6 or 10.7.
10.3 Reclassification Considerations: In evaluating a reclassification petition in accordance with Rules 10.4, 10.5, 10.6, or
10.7, the Director shall consider the factors below, in addition to other relevant information, provided by the facility owner or
operator for the location in question:
10.3.1
Actual or potential threats to public health or the environment;
10.3.2
Surrounding groundwater and surface water quality;
10.3.3
Surrounding groundwater and surface water quality standards;
10.3.4
Current and potential future uses of surrounding property, groundwater, and surface water;
10.3.5
Local and regional groundwater flow direction; and
10.3.6
Feasibility of groundwater remediation to a quality consistent with the standards in Rule 11.
10.4 Upgrading Groundwater Classification: Where it has been proven by clear, convincing and scientifically valid evidence
that the groundwater quality of an area meets the standards of a higher quality groundwater classification than the current
classification or that the classification delineation pursuant to Rule 9.1.2 or 9.1.3(B) or (C) is incorrect, the Director shall
initiate rule-making procedures to upgrade the groundwater classification.
10.5 Downgrading Groundwater Classified GAA to GA: Where it has been proven by clear, convincing and scientifically
valid evidence that groundwater classified GAA is not in an area described in Rule 9.1.1(A) – (C), the Director shall initiate
rule-making procedures for reclassification of such groundwater to GA.
10.6 Downgrading Groundwater Classified GAA or GA to GB: The Director may initiate rule-making procedures for
reclassification of groundwater to GB, provided that it has been demonstrated by clear, convincing and scientifically valid
evidence that the area in question meets the criteria below:
10.6.1 Site conditions are such that the groundwater is known or presumed likely to not meet the standards for
groundwater classified GAA or GA;
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10.6.2 There is no use of groundwater for drinking water, and public water is readily available to all properties within
the area to be reclassified to GB; and
10.6.3 The area in question is located within one of the areas described below:
(A) Contiguous with an existing area classified GB pursuant to Rule 9.1.3(A), provided that the land use activities
in the area in question represent a similar degree of threat to groundwater quality as the contiguous area classified
GB;
(B) Within the permanent waste disposal area as approved by the Director in accordance with the Rhode Island
“Rules and Regulations for the Investigation and Remediation of Hazardous Material Releases” at sites of
historically permitted or approved inactive landfills or inactive disposal sites for solid waste, hazardous waste, or
sewage sludge, where the Director has determined that groundwater remediation to drinking water quality is not
feasible or practical; or
(C) The area immediately surrounding the area classified GB in accordance with Rule 9.1.3(B) or (C) which the
Director has determined is not suitable for public or private drinking water use or the area immediately surrounding
the area classified GC in accordance with Rule 9.1.4, which the Director has determined is not suitable for public or
private drinking water use.
10.7 Downgrading of Groundwater Classification to GC
10.7.1 Groundwater reclassification to GC is required for proposed sites for solid waste landfills and proposed sites for
hazardous waste disposal facilities. Such facilities are the only uses for which groundwater will be reclassified to GC.
10.7.2 Groundwater reclassification to GC will not be considered until an application for a solid waste disposal license
has been filed with the Department pursuant to the Solid Waste Regulations No.1 – No.8 and amendments thereto, or
until an application for a hazardous waste disposal facility has been filed with the Department pursuant to the “Rules
and Regulations for Hazardous Waste Management”.
10.7.3 Groundwater classified GA and GB may be reclassified to GC for proposed sites for solid waste landfills and
proposed sites for hazardous waste disposal facilities. Groundwater classified GAA shall not be reclassified to GC.
10.7.4 In order to reclassify groundwater to GC, the applicant must submit to the Department a site-specific study which
demonstrates by clear, convincing, and scientifically valid evidence that the groundwater quality standards for GC in
Rule 11.4 will be met. The study shall include, but not be limited to, the following:
(A) A locus map using the U.S. Geological Survey 7.5 minute quadrangle map;
(B) Site plan at an appropriate scale (minimum scale of one inch equals fifty feet (1"=50')) to adequately show the
location on and immediately surrounding the site of the following: property boundaries, buildings and other
structures, roads, surface topography, watercourses, wells, water lines, sewer lines, onsite wastewater treatment
systems and other waste disposal areas, and any other significant site features;
(C) Depth to groundwater, water table elevations, hydraulic gradient, groundwater flow direction, groundwater
flow velocity, and water table map;
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(D) Description of the unconsolidated materials (in both the unsaturated and saturated zones), including
permeability, porosity, degree of stratification, and the capacity for pollutant attenuation;
(E) Depth to bedrock and bedrock characteristics, to include, but not be limited to, weathering, jointing, faulting,
fracture orientation and density;
(F) Aquifer characteristics including saturated thickness, hydraulic conductivity, and transmissivity;
(G) Groundwater quality on-site and surrounding the site;
(H) The hydraulic connection between nearby surface waters and groundwater;
(I) Location and distance off-site of the nearest surface water body that will receive runoff from the site and that
surface water body that will receive groundwater flow from the site and the water quality classification of these
surface water bodies.
(J) Public and private wells:
(i)
Determine the number and location of public wells within three (3) miles of the site and the number and
location of private wells within one (1) mile of the site, or the number and location of such wells within
alternative distances agreed upon by the Director;
(ii) Determine or estimate the well depths;
(K) Current and most probable future uses of surrounding groundwater and surface water;
(L) History of site ownership and operation;
(M)Volume and characteristics of the waste to be disposed of on the site;
(N) Specific methods and procedures to be utilized in the construction, operation, and maintenance of the facility
necessary to contain or prevent migration of pollutants;
(O) Evaluation of the potential for migration of pollutants from the site and identification of potential impacts
to groundwater and associated surface waters from the proposal.
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RULE 11. GROUNDWATER QUALITY STANDARDS AND PREVENTIVE ACTION LIMITS
11.1 The Director shall establish groundwater quality standards to be used in determining compliance with the groundwater
classifications, including, but not limited to, compliance of proposed discharges to groundwater, existing discharges to
groundwater, groundwater remediation activities, and other facilities and activities that have an actual or potential adverse
impact on groundwater quality.
11.2 Class GAA and Class GA Groundwater Quality Standards: Class GAA and class GA groundwater are suitable for
drinking water use without treatment, and therefore, both classes are subject to the same groundwater quality standards below
in 11.2.1 – 11.2.4. Exceedances of the groundwater quality standards that are determined by the Director to be caused by
naturally occurring conditions will not be considered a violation of the groundwater quality standards In those areas where
the groundwater is classified GAA (or GA) and the groundwater does not meet the groundwater quality standards, the
groundwater classification remains GAA (or GA) with the goal to regain compliance with the groundwater quality standards.
11.2.1 Pollutants shall not be in groundwater classified GAA or GA, except within an approved pollutant discharge
zone or residual zone (as provided for in Rules 13.2 and 13.3 respectively), in any concentration which will adversely
affect the groundwater as a source of potable water or which will adversely affect other beneficial uses of the
groundwater, to include but not be limited to recreational, agricultural and industrial uses and the preservation of fish
and wildlife habitat through the maintenance of surface water quality.
11.2.2 The numerical groundwater quality standards for specific substances in class GAA and class GA are listed in
Table 1, which, except where indicated, shall be the federal maximum contaminant levels for drinking water established
by the United States Environmental Protection Agency. For a substance not listed in Table 1, the groundwater quality
standard for class GAA and GA groundwater shall be determined by the Director on a case-by-case basis using United
States Environmental Protection Agency health advisories and other public health information.
11.2.3 Groundwater classified GAA and GA shall be of a quality which the Director determines does not violate or
have any reasonable potential to cause a violation of surface water quality standards established by the Rhode Island
“Water Quality Regulations”.
11.2.4 Groundwater classified GAA and GA shall not have non-aqueous phase liquids present in either a mobile or
immobile state at or below the surface of the water table.
11.3 Class GAA and GA Preventive Action Limits: Class GAA and class GA groundwater are subject to the preventive
action limits defined below:
11.3.1 The preventive action limits shall be set at 50% of the numerical groundwater quality standards established
pursuant to Rule 11.2.2.
11.3.2 The preventive action limits shall be used in monitoring discharges to groundwater approved by the Director.
Preventive action limits are not applicable in determining groundwater remediation objectives.
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TABLE 1. Numerical Groundwater Quality Standards and Preventive Action Limits for Class GAA and Class GA.
Standards and Action Limits are for unfiltered samples.
Substance
Groundwater Quality Standard
Preventive Action Limit
(milligrams per liter, except as noted)
A. Inorganic Chemicals
Antimony
0.006
0.003
Arsenic
0.010
0.005
Asbestos
7 million
fibers/l
3.5 million
fibers/l
Barium
2
1
Beryllium
0.004
0.002
Cadmium
0.005
0.0025
Chromium (total)
0.1
0.05
Copper
1.3
0.65
Cyanide
0.2
0.1
Fluoride
4
2
Lead
0.015
0.0075
Mercury
0.002
0.001
Nitrate (as N)
10
5
Nitrite (as N)
1
0.5
Nitrate/Nitrite (total)
10
5
Selenium
0.05
0.025
Thallium
0.002
0.001
B. Organic Chemicals
Alachlor
0.002
0.001
Atrazine
0.003
0.0015
Benzene
0.005
0.0025
Benzo(a)pyrene
0.0002
0.0001
Carbofuran
0.04
0.02
Carbon tetrachloride
0.005
0.0025
Chlordane
0.002
0.001
Chlorobenzene
0.1
0.05
2,4-D
0.07
0.035
Dalapon
0.2
0.1
Di(2-ethylhexyl)adipate
0.4
0.2
Di(2-ethylhexyl)phthalate
0.006
0.003
Dibromochloropropane (DBCP)
0.0002
0.0001
Dichlorobenzene o-
0.6
0.3
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TABLE 1. (continued)
Substance
Groundwater Quality Standard Preventive Action Limit
(milligrams per liter, except as noted)
Dichlorobenzene p-
0.075
0.0375
Dichloroethane (1,2-)
0.005
0.0025
Dichloroethylene (1,1-)
0.007
0.0035
Dichloroethylene (cis-1,2-)
0.07
0.035
Dichloroethylene(trans-1,2-)
0.1
0.05
Dichloromethane
0.005
0.0025
Dichloropropane (1,2-)
0.005
0.0025
Dinoseb
0.007
0.0035
Diquat
0.02
0.01
Endothall
0.1
0.05
Endrin
0.002
0.001
Ethylbenzene
0.7
0.35
Ethylene dibromide (EDB)
0.00005
0.000025
Glyphosate
0.7
0.35
Heptachlor
0.0004
0.0002
Heptachlor epoxide
0.0002
0.0001
Hexachlorobenzene
0.001
0.0005
Hexachlorocyclopentadiene
0.05
0.025
Lindane
0.0002
0.0001
Methoxychlor
0.04
0.02
Methyl tertiary butyl ether (Note 1)
0.04
0.02
Naphthalene (Note 1)
0.1
0.05
Oxamyl (Vydate)
0.2
0.1
Pentachlorophenol
0.001
0.0005
Picloram
0.5
0.25
Polychlorinated biphenyls
0.0005
0.00025
Simazine
0.004
0.002
Styrene
0.1
0.05
2,3,7,8-TCDD (Dioxin)
3E-08
1.5E-08
Tetrachloroethylene
0.005
0.0025
Toluene
1.0
0.5
Toxaphene
0.003
0.0015
2,4,5-TP (Silvex)
0.05
0.025
Trichlorobenzene (1,2,4)
0.07
0.035
Trichloroethane (1,1,1-)
0.2
0.1
Trichloroethane (1,1,2)
0.005
0.0025
Trichloroethylene (TCE)
0.005
0.0025
Trihalomethanes (total)
0.080
0.040
Vinyl Chloride
0.002
0.001
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TABLE 1. (continued)
Substance
Groundwater Quality Standard Preventive Action Limit
(milligrams per liter, except as noted)
Xylenes
10
5
C. Microbiological
Total Coliform Bacteria
zero
zero
Viruses
zero
zero
D. Radionuclides
Gross Alpha Particle Activity
15 pCi/liter
7.5 pCi/liter
Gross Beta Particle Activity
4 mrem/yr
2 mrem/yr
Radium 226 and Radium 228 combined
5 pCi/liter
2.5 pCi/liter
Uranium
0.030 mg/L
0.015 mg/L
Note 1: A federal maximum contaminant level has not been adopted for these chemicals.
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11.4 Class GB and GC Groundwater Quality Standards: Classification of groundwater as GB or GC does not convey the
right to degrade groundwater quality. Limited degradation of groundwater quality may occur as a result of legally authorized
activities related to siting, permitting and remediation where groundwater is classified GB or GC. In those areas where the
groundwater is classified GB (or GC) and the groundwater does not meet the groundwater quality standards, the groundwater
classification remains GB (or GC) with the goal to regain compliance with the groundwater quality standards.
Groundwater classified GB and GC shall be of a quality which the Director determines does not:
11.4.1 Threaten public health or the environment;
11.4.2 Violate or have a reasonable potential to cause a violation of surrounding groundwater quality standards;
11.4.3 Adversely impact or have a reasonable potential to adversely impact current or future uses of property,
groundwater, or surface water;
11.4.4 Violate or have any reasonable potential to cause a violation of surface water quality standards established by the
Rhode Island “Water Quality Regulations”; and
11.4.5 Have non-aqueous phase liquids present in either a mobile or immobile state at or below the surface of the water
table.
11.5 Proposed activities where the groundwater is classified GB in accordance with Rule 9.1.3(B) – (D) that would
otherwise be prohibited in the surrounding areas where the groundwater is classified GA or GAA may at the Director’s
discretion be subject to the Department’s review by means of a groundwater quality certification in accordance with Rule 17
to ensure that the surrounding groundwater quality is protected.
11.6 In determining compliance with the groundwater quality standards for class GB and class GC at a facility, the Director
may consider the factors below, in addition to other relevant information, provided by the facility owner or operator:
11.6.1 Surrounding groundwater quality;
11.6.2 Groundwater classification surrounding the facility;
11.6.3 Surface water classification within the facility boundaries and surrounding the facility;
11.6.4 Current and proposed future uses of groundwater and surface water at or within the facility boundaries;
11.6.5 Current and proposed future uses of the facility;
11.6.6 Uses of surrounding property, groundwater and surface water;
11.6.7 Hydrogeologic characteristics of the facility and surrounding the facility, including, but not limited to,
groundwater flow direction, hydraulic gradient, type of subsurface materials, and depth to bedrock;
11.6.8 Actual and potential routes for human exposure and points of human exposure to the pollutant(s);
11.6.9 Man-made pathways for pollutant movement off-site, e.g., underground utility lines; and
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11.6.10 Persistence and mobility of the pollutant(s) in the subsurface and the toxicity of the pollutant(s).
RULE 12. DETERMINATION OF COMPLIANCE WITH GROUNDWATER QUALITY STANDARDS AND
PREVENTIVE ACTION LIMITS
12.1 Compliance with the groundwater quality standards and preventive action limits shall be determined through analytical
tests of groundwater quality by the facility owner or operator. Where applicable, the Director may also require analytical
tests of the effluent prior to the discharge to the groundwater. The Director may request verification of any test data or collect
separate samples if it is deemed necessary.
12.2 Sampling
12.2.1 Groundwater samples and effluent samples shall be collected, stored, transported, and analyzed in accordance
with the most recent United States Environmental Protection Agency approved procedures; the most recent "Standard
Methods for the Examination of Water and Wastewater" (American Public Health Association, et al.); or alternative
methods approved by the Director. The Director has the authority to determine which approved method is applicable
for the sampling event.
12.2.2 Groundwater and effluent sampling frequency and the list of parameters to test for shall be proposed to the
Director by the facility owner or operator. The Director's determination of sampling frequency and the parameters to
test for shall be made, in part, utilizing information provided by the facility owner or operator regarding the type of
facility, waste generated, waste disposed of on site, materials stored or utilized on site and any site specific
hydrogeologic characteristics that may be required by the Director. Groundwater shall be analyzed for constituents of
concern, and this may include constituents that do not have numerical groundwater quality standards. In accordance
with approval from the Director, continual groundwater monitoring at a site may be for a specific subset of parameters.
12.3 Groundwater Monitoring
12.3.1 All facilities that are required by the Director to monitor groundwater quality pursuant to these Rules shall
implement a groundwater monitoring plan approved by the Director that meets the requirements of Rule 12.3.2.
Groundwater monitoring plans approved pursuant to other Department of Environmental Management rules and
regulations shall be exempt from this requirement.
12.3.2 The groundwater monitoring plan shall include, at minimum, the following:
(A) A locus map using the U.S. Geological Survey 7.5 minute quadrangle map;
(B) Site plan at an appropriate scale (minimum scale of one inch equals fifty feet (1"=50')) to adequately show the
monitoring well locations, well casing elevations, and the location on and immediately surrounding the site of the
following: property boundaries, buildings and other structures, roads, surface topography, watercourses, wells,
water lines, sewer lines, onsite wastewater treatment systems and other waste disposal areas, and any other
significant site features;
(C) A sufficient number of wells (minimum of three) at the appropriate locations and depths to permit detection of
any pollutants in the groundwater;
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(D) Well logs with detailed lithologic and well construction information; and
(E) Sampling schedule pursuant to Rule 12.1.2.
12.3.3 Monitoring well construction shall be in compliance with the standards set forth in Appendix 1.
12.3.4 Minimum site monitoring requirements:
(A) The static water table elevation shall be recorded at the time of monitoring; and
(B) A log containing static water table elevations and the sample analyses shall be maintained on-site by the
facility owner or operator.
12.3.5 Copies of sample results and water table measurements shall be submitted to the Director within thirty (30) days
of the receipt of such information by the facility owner or operator.
12.3.6 An approved groundwater monitoring plan shall be valid for a duration specified by the Director.
12.3.7 There shall be no change in a groundwater monitoring plan without the approval of the Director. The Director
may require a change in an approved monitoring plan where such change is necessary to determine compliance with the
groundwater quality standards.
12.3.8 Any person transferring ownership or control of a facility having an approved groundwater monitoring plan
shall notify the Director of such transfer not less than thirty (30) days prior to the effective date of such transfer.
12.3.9 Groundwater monitoring required by the Director shall not be terminated without the approval of the Director.
12.3.10 When groundwater monitoring has been terminated, the monitoring wells shall be abandoned in accordance
with the procedures established in Appendix 1.
RULE 13. POINTS OF COMPLIANCE
13.1 Points of compliance with the groundwater quality standards and preventive action limits must be approved by the
Director. The Director may designate any point where groundwater is withdrawn for use or monitored as a point of
compliance. Points of compliance shall be within the area of known or suspected groundwater pollution unless a pollutant
discharge zone or residual zone is designated pursuant to Rule 13.2 and 13.3, respectively. If a pollutant discharge zone or
residual zone is designated, the points of compliance shall be at the boundary of such zone.
13.2 Pollutant Discharge Zone: In determining compliance with the groundwater quality standards and preventive action
limits in these Rules for a discharge to groundwater where the groundwater is classified GAA or GA, the Director may
approve, deny, or modify a pollutant discharge zone proposed by a facility owner or operator. Within this pollutant discharge
zone, the pollutant concentrations in groundwater are allowed to be greater than the groundwater quality standards.
Acceptable pollutant concentrations in groundwater within a pollutant discharge zone shall be determined by the Director on
a case-by-case basis.
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13.2.1 The facility owner or operator proposing a pollutant discharge zone shall provide the Director with sufficient
information on the site's hydrogeology and the characteristics of the discharge to groundwater to support the proposed
pollutant discharge zone delineation.
13.2.2 A groundwater monitoring plan prepared pursuant to Rule 12.2 shall be submitted to the Director at the same
time that a pollutant discharge zone is proposed, unless the Director determines that groundwater monitoring is not
necessary.
13.2.3 Prior to approval of a pollutant discharge zone, the facility owner or operator shall demonstrate by clear,
convincing, and scientifically valid evidence that:
(A) All practical alternatives to a discharge to groundwater have been evaluated and no technically or
economically feasible alternative exists;
(B) Every practical effort has been made to limit the pollutant concentrations in the discharge to groundwater by
such means as, but not limited to, reducing the quantity of potentially contaminating substances in use, use of
alternative substances, changes in the operational procedures at the facility, and pretreatment of the effluent;
(C) The pollutant discharge zone is limited to the smallest area that is technically and economically feasible;
(D) The facility owner or operator has acquired rights to the pollutant discharge zone as evidenced by ownership
of the land within the pollutant discharge zone, ownership of an easement to such land, or otherwise controls such
land to the Director's satisfaction. Any such easement or other control mechanism shall prohibit use of the
groundwater for a drinking water supply and provide the right to enter the pollutant discharge zone for
groundwater monitoring and, if necessary, remediation activities.
(E) The discharge to groundwater and the resulting groundwater quality in the pollutant discharge zone do not
represent a threat to public health or the environment;
(F) There will be no violation of the groundwater quality standards established in Rule 11 beyond the pollutant
discharge zone as a result of the proposed discharge;
(G) There will be no adverse impact on existing public or private wells as a result of the proposed discharge; and
(H) The groundwater within the pollutant discharge zone will not cause a violation of the surface water quality
standards established by the Rhode Island “Water Quality Regulations” as a result of the proposed discharge.
13.3 Residual Zone: In determining compliance with the groundwater quality standards and preventive action limits in these
Rules for groundwater remediation activities where the groundwater is classified GAA or GA, the Director may designate or
approve, deny, or modify the designation of a residual zone proposed by the facility owner or operator.
13.3.1 Within this residual zone, the pollutant concentrations in groundwater are allowed to be greater than the
groundwater quality standards. Acceptable pollutant concentrations in the groundwater within a residual zone shall be
determined by the Director on a case-by-case basis. The Director may require that the groundwater quality within the
residual zone be monitored.
13.3.2 Prior to approval of a residual zone, the facility owner or operator shall demonstrate by clear, convincing and
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scientifically valid evidence that:
(A) The source of the pollutants has been removed or controlled to the satisfaction of the Director and every
practical effort has been made to decrease the pollutant concentrations in the residual zone;
(B) The residual zone is limited to the smallest area that is technically and economically feasible;
(C) The facility owner or operator has acquired rights to the residual zone as evidenced by ownership of the land
within the residual zone, ownership of an easement to such land, or otherwise controls such land to the Director's
satisfaction. Any such easement or other control mechanism shall prohibit use of the groundwater for a drinking
water supply and provide the right to enter the residual zone for groundwater monitoring and remediation
activities;
(D) The pollutant concentrations in the groundwater within the residual zone do not or will not represent a threat to
the public health or the environment;
(E) There will be no adverse impact on existing public or private wells as a result of the residual zone;
(F) There will be no violation of the groundwater quality standards established in Rule 11 beyond the residual zone;
and
(G) The groundwater within the residual zone will not cause a violation of the surface water quality standards
established by the Rhode Island “Water Quality Regulations”.
RULE 14. NOTIFICATION TO DEM OF VIOLATIONS OF PREVENTIVE ACTION LIMITS AND
GROUNDWATER QUALITY STANDARDS
14.1 Exemptions from Provisions of This Rule:
14.1.1 Persons subject to the Rules below shall follow notification and reporting requirements therein and in doing so
are exempt from the provisions of Rule 14 provided that the notification documents any violations of the groundwater
quality standards in Rule 11:
(A) Rhode Island “Rules and Regulations for Underground Storage Facilities Used for Petroleum Products and
Hazardous Materials”;
(B) Rhode Island “Rules and Regulations for the Investigation and Remediation of Hazardous Material Releases”;
and
(C) Rhode Island “Solid Waste Regulations No.1 through No. 8”.
14.1.2 Persons reporting spills of chemical or petroleum products to the Department pursuant to the immediate
notification requirements of other state or federal laws and regulations are exempt from provisions Rule 14.
14.1.3 Owners of property served by private wells used exclusively for residential purposes are exempt from the
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provisions of Rule 14.
14.2 Notification: Facility owners or operators that discharge to groundwater or have had a discharge or release to
groundwater shall notify the Department within fifteen (15) days of the discovery when any of the following occur:
14.2.1
A preventive action limit has not been met at any point of compliance at a facility that has a discharge to
groundwater approved by DEM where the groundwater is classified GAA or GA;
14.2.2
A groundwater quality standard has not been met at any point of compliance at a facility in any groundwater
classification;
14.2.3
An alternative notification level established under a groundwater monitoring plan approved by the Director
pursuant to Rule 12 or other groundwater monitoring plan approved by the Director pursuant to other rules and
regulations of the Department or the federal government has not been met; or
14.2.4
The facility owner or operator has reasonable cause to believe that a discharge or release has occurred that
may result in the violation of a preventive action limit or groundwater quality standard.
14.3 Notification Contents: Notification shall include, but not be limited to, the following:
14.3.1 Name, address, telephone number of person notifying the Department and of the facility owner or operator;
14.3.2 Date and time of the discovery and the circumstances surrounding the discovery of the occurrence requiring
notification;
14.3.3 Groundwater classification of the site;
14.3.4 Location of the occurrence and a legal description of the site (plat and lot);
14.3.5 Concentration of the pollutant(s) identified in the groundwater when notification is pursuant to Rule 14.2.1-
14.2.3;
14.3.6 Identification of the pollutant(s) in the discharge or release when notification is pursuant to Rule 14.2.4;
14.3.7 Initial determination of the source of the pollutant(s) and an estimate of the extent of pollution; and
14.3.8 Measures taken or proposed to be taken at the time of notification.
14.4 Certification Requirements: The notification shall include a statement signed by the facility owner or operator, or an
authorized representative that is responsible for the preparation and submittal of the notification certifying to the best of
their knowledge that the notification is complete and accurate.
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RULE 15. FACILITY OWNER OR OPERATOR RESPONSES TO VIOLATIONS OF PREVENTIVE
ACTION LIMITS AND GROUNDWATER QUALITY STANDARDS
15.1 Violation of a Preventive Action Limit: When a preventive action limit has not been met, the facility owner and
operator are responsible for taking actions, which shall be subject to the approval of the Director, to meet the following
objectives at the point of compliance:
15.1.1 Minimize the concentration of the pollutant in the groundwater where technically and economically feasible;
15.1.2 Regain and maintain compliance with the preventive action limit, unless the Director determines that it is not
technically or economically feasible to attain the preventive action limit concentration, in which case the owner or
operator shall achieve compliance with the lowest possible concentration that is technically and economically feasible;
and
15.1.3 Ensure that the groundwater quality standard is met at any point of compliance.
15.2 Violation of a Groundwater Quality Standard: When a groundwater quality standard has not been met, the facility
owner and operator are responsible for taking actions, which shall be subject to the approval of the Director, to regain and
maintain compliance with the groundwater quality standard at the point of compliance.
15.3 Potential for Violation of Preventive Action Limit or Groundwater Quality Standard: Where the Director has reason to
believe that a discharge or release has occurred which may enter the groundwaters of the state and result in the violation of a
preventive action limit or groundwater quality standard, the Director is authorized to require the facility owner or operator to
take action pursuant to Rule 15.4.
15.4 Responses to Violation of a Preventive Action Limit or a Groundwater Quality Standard: When a preventive action
limit or groundwater quality standard is not met at a point of compliance or a discharge or release is suspected that may result
in the violation of a preventive action limit or groundwater quality standard, the Director may require the facility owner or
operator to take any one or more of the responses below:
15.4.1 Resample groundwater quality at the point of compliance.
15.4.2 Collect and submit additional data on groundwater quality on site or surrounding the site, hydrogeologic
characteristics, or facility practices.
15.4.3 Arrange for the sampling of private wells which may be adversely affected. Notify public water systems that
may be adversely affected and reimburse the public water systems for the costs of additional water quality monitoring
necessary to ensure public health.
15.4.4 Install and sample monitoring wells. Such wells shall be in compliance with the construction standards in
Appendix 1, unless otherwise approved by the Director.
15.4.5 Require the establishment of a groundwater monitoring plan pursuant to Rule 12.2 or other groundwater
monitoring plan approved by the Director pursuant to other regulations of the Department or the federal government, or
require a change in an existing groundwater monitoring plan.
15.4.6 Require a revision of the operational procedures at the facility.
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15.4.7 Require a change in the design or construction of the facility.
15.4.8 Require an alternate method of waste treatment or disposal.
15.4.9 Require the facility owner or operator to conduct a groundwater assessment and prepare a report pursuant to Rule
15.6, or another report pursuant to other applicable Department rules and regulations, that is subject to the Director's
review and approval. Based on the results of this report, the Director may require further investigation.
15.4.10 Require prohibition of an activity.
15.4.11 Require the facility owner or operator to provide drinking water to those persons that do not have a potable
water supply (for violation of groundwater quality standard only).
15.4.12 Require the facility owner or operator to conduct a groundwater investigation and prepare a report pursuant to
Rule 15.7, or another report pursuant to other applicable Department rules and regulations, to adequately assess the
nature and extent of pollution. Such report shall be subject to the Director's review and approval.
15.4.13 Require remedial action to restore groundwater quality to levels established by the Director pursuant to Rule 16.
15.5 Determination of the Response: In evaluating a violation of a preventive action limit or groundwater quality standard,
and in determining the appropriate response required of the facility owner or operator pursuant to Rule 15.4, the Director may
consider the following information provided by the facility owner or operator, in addition to all other relevant information:
15.5.1 Surrounding groundwater quality;
15.5.2 Geographic extent of pollutant migration;
15.5.3 Hydrogeologic conditions;
15.5.4 Present and future uses of the groundwater on-site and in the surrounding area;
15.5.5 Reliability of sampling data;
15.5.6 Performance of the activities at the facility;
15.5.7 Water quality standards established by the Rhode Island “Water Quality Regulations” for those surface waters
receiving groundwater from the site; and
15.5.8 Other known or suspected sources in the area of the substance that is identified as in violation of the preventive
action limit or groundwater quality standard.
15.6 Groundwater Assessment Report
15.6.1 A groundwater assessment report required pursuant to Rule 15.4.9 shall be prepared by a person with appropriate
qualifications, and it shall include, but not be limited to, the following information, unless otherwise specified by the
Director:
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(A) All information previously reported to the Director pursuant to Rule 14 and information reported to the
Director in accordance with emergency response procedures of other applicable state and federal laws and
regulations. The facility owner or operator may elaborate and expand on any and all information found in previous
reports. The facility owner or operator shall correct any incorrect information or interpretations contained in
previous reports as part of the site characterization;
(B) A locus map using the U.S. Geological Survey 7.5 minute quadrangle map;
(C) Description of past and present activities on the site, including a list of past owners and operators of the site
and approximate time periods of occupancy;
(D) A compliance history of the site including any and all past environmental enforcement actions and
documentation of any past discharges or releases;
(E) Site plan at an appropriate scale (minimum scale of one inch equals fifty feet (1"=50')) to adequately show the
location on and immediately surrounding the site of the following: property boundaries, buildings and other
structures, roads, surface topography, watercourses, wells, water lines, groundwater monitoring wells, materials
storage areas (including underground storage tanks), sewer lines, onsite wastewater treatment systems and other
waste disposal areas;
(F) Names and addresses of the owners and tenants of all properties that abut the site;
(G) Description of the site's hydrogeology, including, but not limited to, depth to groundwater, groundwater flow
direction, and a description of the unconsolidated materials, including soil characteristics;
(H) Location and distance off-site of the nearest surface water body that will receive runoff from the site and the
water quality classification of this surface water;
(I) Location of public wells within three (3) miles of the site or within an alternative distance of the site agreed
upon by the Director;
(J) Information regarding private water supply as follows:
(i)
Location of private wells on those properties that are wholly or partially within 500 feet of the site or a
greater distance specified by the Director;
(ii) A description of the water supply sources and services available beyond 500 feet from the site and up to
one mile from the site. The Director may require more specific detail.
(K) Identification of the pollutant(s) and an estimate of the geographic extent and volume of the affected area;
(L) A description of evidence of possible groundwater pollution, including, but not limited to, free liquids, stained
soil, stressed vegetation, and the presence and volume of excavated materials.
(M) Results of any analytical testing of groundwater or soil on the site, including identification of methods used
and sampling protocols;
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(N) Recommendations for further groundwater investigation, groundwater remediation, or other actions; and
(O) Any other factors that the Director has reason to believe are necessary for an adequate groundwater
assessment.
15.6.2
Monitoring wells installed to collect groundwater quality data shall be in compliance with the construction
standards in Appendix 1, unless otherwise approved by the Director.
15.6.3
The groundwater assessment report and any associated progress reports shall include the following statements
signed by an authorized representative of the party specified:
(A) A statement signed by an authorized representative of the person who prepared the groundwater assessment
report certifying, to the best of their knowledge, the accuracy of the information contained in the report; and
(B) A statement signed by the facility owner or operator responsible for the submittal of the groundwater
assessment report certifying, to the best of their knowledge, that the report is a complete and accurate
representation, and that it includes all known facts about the discharge to groundwater or the release that has, or
may result in, the violation of a preventive action limit or groundwater quality standard.
15.7 Groundwater Investigation Report
15.7.1 A groundwater investigation report required pursuant to Rule 15.4.12 shall be prepared by a person with
appropriate qualifications, and it shall include all the elements of a groundwater assessment report described in Rule
15.6, and it shall also include, but not be limited to, the following information:
(A) Complete description of the site's hydrogeology, including, but not limited to, the following:
(i)
Depth to groundwater, water table elevations, hydraulic gradient, groundwater flow direction,
groundwater flow velocity, and water table map;
(ii) Description of the unconsolidated materials (in both the unsaturated and saturated zones), including
permeability, porosity, degree of stratification, and the capacity for pollutant attenuation;
(iii) Depth to bedrock and bedrock characteristics;
(iv) Aquifer characteristics including saturated thickness, hydraulic conductivity, and transmissivity;
(v) The presence and effects of both natural and man-made barriers to and conduits for pollutant migration;
(vi) Surrounding groundwater quality;
(B) Description of the pollutant source and the events that caused the pollution;
(C) Extent of soil pollution;
(D) Extent of groundwater pollution;
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(E) Map showing lines of equal pollutant concentrations in the groundwater; and
(F) Conclusions based on the site data and recommendations for groundwater remediation.
15.7.2 Monitoring wells installed to collect groundwater quality data shall be in compliance with the construction
standards in Appendix 1, unless otherwise approved by the Director.
15.7.3 The groundwater investigation report and any associated progress reports shall include the following statements
signed by an authorized representative of the party specified:
(A) A statement signed by an authorized representative of the person who prepared the groundwater investigation
report certifying, to the best of their knowledge, the accuracy of the information contained in the report; and
(B) A statement signed by the facility owner or operator responsible for the submittal of the groundwater
investigation report certifying, to the best of their knowledge, that the report is a complete and accurate
representation, and that it includes all known facts about the discharge to groundwater or the release that has, or
may result in, the violation of a preventive action limit or groundwater quality standard.
RULE 16. GROUNDWATER REMEDIATION
16.1 Exemptions:
16.1.1 Groundwater remediation plans prepared in accordance with other Department regulations or federal laws and
regulations are exempt from the provisions of Rules 16.4 and 16.5.
16.1.2 Emergency response procedures at sites of groundwater pollution or the threat of pollution are exempt from the
provisions of this Rule, and such procedures shall be conducted in accordance with other applicable state and federal
laws and regulations.
16.2 Groundwater Remediation Objectives: When groundwater remediation is required by the Director, the facility owner
and operator are jointly and severally responsible for designing and implementing efforts to remediate the groundwater to
achieve pollutant concentrations established by the Director. Groundwater remediation activities shall be designed to meet the
following objectives:
16.2.1 Protect public health and the environment;
16.2.2 Ensure compliance with the groundwater quality standards for the classification assigned to the groundwater of
concern;
16.2.3 Eliminate or contain the source of groundwater pollution and minimize the impacted area;
16.2.4 Achieve pollutant concentrations that are consistent with proposed and anticipated future uses of the site;
16.2.5 Prevent an adverse impact on surrounding uses of property, groundwater and surface water;
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16.2.6 Prevent the violation of surrounding groundwater quality standards; and
16.2.7 Prevent the groundwater at the remediation site from causing a violation of the surface water quality standards
established by the Rhode Island “Water Quality Regulations”.
16.3 Considerations for Remediation Decisions: The determination by the Director of groundwater remediation actions
required of an owner or operator, the suitability of proposed remediation techniques, and the acceptable pollutant
concentrations that may remain in groundwater after remediation may be based on, but not limited to, a consideration of:
16.3.1 Relative threat to public health and the environment from the facility;
16.3.2 The physical and chemical characteristics of the pollutant(s), including toxicity, persistence and potential for
migration;
16.3.3 Hydrogeologic characteristics of the site and surrounding the site;
16.3.4 Current and potential future uses of groundwater and surface water at the site and surrounding
the site;
16.3.5 Groundwater classification at the site and surrounding the site;
16.3.6 Other state and federal program priorities;
16.3.7 Relative potential for adverse impacts on surrounding uses of property, groundwater and surface water;
16.3.8 Relative potential for violation of surrounding groundwater quality standards;
16.3.9 Relative potential for the groundwater at the remediation site to cause a violation of the surface water quality
standards established by the Rhode Island “Water Quality Regulations”; and
16.3.10 Reliability and technical feasibility of the proposed technologies for groundwater remediation.
16.4 Groundwater Remediation Plan: Where required by the Director, a groundwater remediation plan shall be prepared by
the facility owner or operator.
16.4.1
The groundwater remediation plan shall consist of, at minimum, the following:
(A) Groundwater assessment report pursuant to Rule 15.6, groundwater investigation report pursuant to Rule 15.7
(if such report was required), and any additional information the Director shall require;
(B) Proposed method for remediation, to include, but not be limited to, the following:
(i)
Justification of the ability of the method to meet the remediation objectives;
(ii) Design standards and technical specifications for the design and construction of any equipment necessary
for the proposed remediation;
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(iii) Diagrams of any piping routes, instrumentation, and process flows; and
(iv) Proposed plans for the disposal of any products or by-products from the remediation activities;
(C) Proposed schedule for implementation of the remediation plan; and
(D) Proposed groundwater monitoring plan pursuant to Rule 12.2.
16.4.2 The groundwater remediation plan and any associated progress reports shall include the following statements
signed by an authorized representative of the party specified:
(A) A statement signed by an authorized representative of the person who prepared the groundwater remediation
plan certifying, to the best of their knowledge, the accuracy of the information contained in the plan; and
(B) A statement signed by the facility owner or operator responsible for the preparation and submittal of the
groundwater remediation plan certifying, to the best of their knowledge, that the plan is complete and accurate.
16.5 Approval of Groundwater Remediation: Groundwater remediation activities shall be proposed and implemented by the
facility owner or operator, and they shall be done in a manner approved by the Director through the issuance of an order
of approval unless otherwise specified by the Director 16.5.1 Upon review of the groundwater remediation plan, the
Director shall approve the plan, approve the plan with conditions, require revisions to the plan, or deny approval of the
plan based on a determination of the plan's ability to meet the groundwater remediation objectives in Rule 16.2.
16.5.2 Orders of approval for groundwater remediation shall be valid for a time period specified by the Director.
16.5.3 Any person transferring ownership or control of a facility having an approved groundwater remediation plan shall
notify the Director of such transfer not less than thirty (30) days prior to the effective date of such transfer.
16.5.4 Implementation of remedial activities approved by the Director does not discharge or otherwise release the
facility owner or operator from responsibility for any adverse impacts to public health and the environment caused by
pollutants in the groundwater at the site.
RULE 17. GROUNDWATER QUALITY CERTIFICATION
17.1 Applicability: Groundwater quality certification may at the Director’s discretion be required for the following:
17.1.1 Proposed activities where the groundwater is classified GB in accordance with Rule 9.1.3(B) – (D) that would
otherwise be prohibited in the surrounding areas where the groundwater is classified GA or GAA (See Rule 11.5); and
17.1.2 Any project or activity that the Department has determined has a reasonable potential to adversely impact
groundwater quality and there is no other Department regulation that addresses the potential impact on groundwater
quality.
17.2 Groundwater quality certifications that have been issued pursuant to these or previously promulgated versions of these
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Rules shall remain in effect until such time that the Department license or permit that triggered the need for a certification has
expired or until the Department specifies otherwise.
17.3 Groundwater Quality Certification Application and Review
17.3.1 All applications for groundwater quality certifications shall be made on forms provided by the Director.
17.3.2 The groundwater quality certification application form shall be accompanied by a non-refundable check for two
hundred dollars ($200.00) payable to the “General Treasurer, State of Rhode Island."
17.3.3 The applicant shall be responsible for providing all information required by the Department in a complete and
accurate manner.
17.3.4 After review of the groundwater quality certification application, the Director shall approve the application in
accordance with Rule 17.4, deny the application, or approve the application with conditions.
17.4 Criteria for Groundwater Quality Certification Approvals: Facility owners or operators that are requesting groundwater
quality certification must show by clear, convincing and scientifically valid evidence that:
17.4.1 There is no reasonable potential for violation of the groundwater quality standards in Rule 11, except within a
pollutant discharge zone approved pursuant to Rule 13; and
17.4.2 There is no reasonable potential for groundwater impacted by the proposed project to cause a violation of surface
water quality standards established by the Rhode Island “Water Quality Regulations”.
RULE 18. WELLHEAD PROTECTION
(See Appendix 4 for a small scale Wellhead Protection Area Map.)
18.1 Delineation of Wellhead Protection Areas
18.1.1 Wellhead protection areas for each public well in Rhode Island approved by the Rhode Island Department of
Health shall be established by the Department of Environmental Management in accordance with the delineation
methods below in (A)–(C), unless a refined delineation pursuant to Rule 18.2 is approved by the Department. (See
Appendix 5 for a description of the methodology.)
(A) The wellhead protection area for community and non-transient non-community wells completed in stratified
drift will be determined by application of an analytical model for the delineation in the stratified drift and by using
hydrogeologic mapping in the upgradient till deposits. If such delineation is not available at the time of the well’s
approval by the Rhode Island Department of Health, an interim wellhead protection area shall be designated as a
2000 foot radius circle, until such time that a delineation is completed by the Department of Environmental
Management.
(B) The wellhead protection area for wells completed in bedrock (community and non-community) is a calculated
fixed radius based on the well’s pump rate with a minimum radius of 1750 feet. See Table 2 for a list of pump rates
and corresponding wellhead protection area radii.
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(C) The wellhead protection area for any other groundwater source, including springs, wells completed in till
deposits, transient non-community wells completed in stratified drift, and any well where the geologic formation
supplying the water is unknown, will be a radius of 1750 feet.
18.1.2 Wellhead protection areas in Rhode Island include those portions of wellhead protection areas for public wells in
Connecticut and Massachusetts that extend into Rhode Island as a result of delineations done in accordance with a
United States Environmental Protection Agency approved Wellhead Protection Program or Source Water Protection
Program in Connecticut or Massachusetts.
18.1.3 In the event that the boundary of a wellhead protection area delineated by the Department is in dispute, the
burden of proof shall be on the person disputing the boundary to show to the satisfaction of the Department a more
accurate delineation. If the wellhead protection area in question is for a community water supply well, the procedure in
Rule 10 for Modification of Groundwater Classification must be followed.
Table 2. Wellhead Protection Area Radius for Bedrock Wells
(gpm = gallons per minute; For pumping rates not provided below, the Wellhead Protection Area Radius shall be
calculated using the formula in Appendix 5.)
Pumping Rate
Radius
Pumping Rate
Radius
(gpm)
(ft)
(gpm)
(ft)
≤10
1750
23
2411
11
1820
24
2440
12
1872
25
2466
13
1920
30
2568
14
1965
35
2638
15
2008
40
2689
16
2087
45
2729
17
2153
50
2760
18
2211
60
2806
19
2261
70
2875
20
2305
80
2985
21
2344
90
3068
22
2380
100
3133
18.2 Refined Wellhead Protection Areas: The Department, water suppliers, or other state or federal agencies may delineate
refined wellhead protection areas, which are prepared using more complex methods or additional data than that used in the
Director's initial delineation. Requests for Department approval of refined delineations shall follow the procedure below:
18.2.1 Requests for approval of refined wellhead protection areas shall be submitted in writing to the Director and shall
include, at minimum:
(A) A map of the well location and proposed refined wellhead protection area using the United States Geological
Survey 7.5 minute quadrangle map (scale of 1:24000);
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(B) Detailed description of the mapping methodology;
(C) List of data sources;
(D) Detailed description of field methods and results for such activities as pump tests and water table
measurements;
(E) Detailed description of modelling method, assumptions, results, and principal model input and output values;
and
(F) Water table map used in the refined wellhead protection area mapping;
18.2.2 Additional information may be required by the Director in order to adequately review a proposed refined
wellhead protection area.
18.2.3 After reviewing the proposed refined wellhead protection area, the Director shall accept it, deny it, or accept it
with conditions. An accepted refined wellhead protection area delineation will be incorporated into the official wellhead
protection area map in accordance with Rule 18.3 and shall supersede the Director's initial wellhead protection area
delineation.
18.3 Wellhead Protection Area Maps: The wellhead protection areas shall be delineated on 1:24000 scale maps. The
1:24000 scale maps shall be on file for review at the Rhode Island Department of Environmental Management, 235
Promenade Street, Providence, RI 02908. Smaller scale maps may be made available from the Department at the above
address, and the wellhead protection areas may be viewed on the DEM website. The Director shall periodically initiate rule-
making procedures to update the wellhead protection maps, which may involve changing wellhead protection area
delineations, incorporating additional wellhead protection areas or deleting wellhead protection areas.
18.4 Deletion of Wells from the Wellhead Protection Area Map: A public well and its wellhead protection area delineation
will be deleted from the Department's Wellhead Protection Area map and no longer subject to provisions of these Rules when
the Rhode Island Department of Health has determined that the well is no longer an approved public drinking water supply
and the Director has determined that maintaining the wellhead protection area no longer serves the public interest. The
Director’s determination shall be based on the available information, period of disuse, and the absence of any known dispute
concerning deleting the well from the Wellhead Protection Area map. Such determination shall be made in a manner
consistent with the Rhode Island State Guide Plan.
18.5 Addition of Wells to the Wellhead Protection Area Map: A public well and its wellhead protection area delineation will
be added to the Department’s Wellhead Protection Area map and subject to the provisions of these Rules at the time of
approval by the Rhode Island Department of Health as a public drinking water supply or if the Director has determined that it
serves the public interest to add a wellhead protection area for a well site not yet approved by the Department of Health, but
which will likely be used for public drinking water supply in the future.
18.6 Wellhead Protection Planning: The Rhode Island Wellhead Protection Program (February 1990) requirement for
municipalities and large water suppliers with a groundwater source(s) of supply to inventory potential pollution threats in the
wellhead protection areas and develop a wellhead protection plan will be met by:
18.6.1 Municipal comprehensive plans, prepared pursuant to the Rhode Island Comprehensive Planning and Land Use
Act (RIGL Chapter 45-22.1), determined by the Department to be consistent with the Department’s Groundwater
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Protection Program goals and policies. These goals and policies for communities dependent on groundwater for
drinking water require, at minimum: a pollution threat assessment; identification of protection strategies, which must at
minimum include public education on groundwater protection; coordination, where appropriate, with neighboring states,
communities and water suppliers; and a procedure for implementing the chosen strategies; and
18.6.2 Large water suppliers subject to the requirements of the Rhode Island Water Resources Board “Rules and
Procedures for Water Supply System Management Planning” that are determined to be in compliance with the Water
Quality Protection Component of the “Rules and Procedures for Water Supply System Management Planning”.
RULE 19. VARIANCES
19.1 Variance Requests: A facility owner or operator may submit a written request to the Director for a variance from any of
the provisions of these Rules. Such request for a variance shall include at a minimum:
19.1.1 Name and address of the facility owner or operator, and the name and location of the facility for which the owner
or operator seeks a variance;
19.1.2 A list of the names and addresses of the owners and tenants of all properties that abut the facility;
19.1.3 Identification of the specific Rule or Rules from which a variance is requested;
19.1.4 A statement of the reasons for which the facility owner or operator seeks a variance. This statement shall specify
the reasons that the facility owner or operator is unable to comply with these Rules, why a variance is necessary, and the
reasons why a hardship is alleged. The person seeking the variance should separately and by number list each reason
and any other mitigating factors he believes the Director should consider; and
19.1.5 An explanation that the alternative procedures requested are substantially equivalent to the Rules herein in
achieving protection of the public health and the environment.
19.2 Variance Decisions
19.2.1 The Director may issue a variance under this Rule when the facility owner or operator proves by clear,
convincing and scientifically valid evidence that:
(A) Compliance with these Rules would cause unreasonable or undue hardship;
(B) The issuance of the variance will have no adverse effect on public health and the environment; and
(C) The alternative procedures requested are substantially equivalent to the Rules herein in achieving protection of
the public health and the environment.
19.2.2 If the Director determines that there is widespread public interest or that the variance request raises major issues
that could affect other facilities, then the Director may schedule a public hearing to solicit public comment prior to
rendering a decision on the variance request.
19.2.3 The Director's decision to grant or deny a variance shall be in writing and may, as a condition of granting the
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variance, impose appropriate requirements necessary to protect the public health and the environment.
RULE 20. ENFORCEMENT
20.1 Where the Director has reason to believe that a violation of any part of the Rules herein has occurred, the Director may
issue a notice of violation or immediate compliance order pursuant to Chapter 42-17.1 of the Rhode Island General Laws of
1956, as amended.
20.2 For violations that are of a continuing nature, each and every day that the violation exists shall constitute a separate and
distinct violation.
RULE 21. APPEALS
Any person affected by a decision of the Director pursuant to these Rules may, in accordance with the Rhode Island
“Administrative Rules of Practice and Procedure for the Administrative Adjudication Division for Environmental Matters”,
file a claim for an adjudicatory hearing to review the decision. All appeals shall be in writing and shall be filed with and
received by the Department’s Administrative Adjudication Division within thirty (30) days after the effective date of the
denial of the subject application. The party appealing a Department decision bears the burden of proving that their
application complies with all requirements of the Rules herein.
RULE 22. SUPERSEDED REGULATIONS
22.1 Effective June 18, 1992, Rule 9.03 (Monitoring Well Abandonment) of the Rhode Island “Rules and Regulations
Governing the Enforcement of Chapter 46-13.2 Relating to the Drilling of Drinking Water Wells”, filed with the Secretary of
State December 15, 1989, is hereby revoked and superseded by section 8.0 of Appendix 1 of the Rules herein.
22.2 On the effective date of these Rules, all previous Rules and Regulations, and any policies regarding the administration
and enforcement of the Groundwater Protection Act (Rhode Island General Laws, Chapter 46-13.1) shall be superseded.
However, any enforcement action taken by, or application submitted to, the Department prior to the effective date of these
Rules shall be governed by the Rules and Regulations in effect at the time the enforcement action was taken, or application
filed.
RULE 23. PENALTIES
Penalties will be assessed in accordance with the Department's “Rules and Regulations for the Assessment of Administrative
Penalties”, for any violation of these Rules.
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APPENDIX 1
Construction Standards for Monitoring Wells and
Abandonment Procedures for Monitoring Wells, Piezometers
and Other Subsurface Borings
1.
Purpose: This Appendix provides minimum standards for the construction of monitoring wells for the procurement of
samples representative of groundwater and abandonment procedures for monitoring wells, piezometers and other subsurface
borings. These minimum standards are consistent in most instances with the American Society for Testing and Materials
(ASTM) standards listed below, which should be consulted for more detailed information. Where the requirements in this
Appendix differ from the ASTM standards, the requirements herein govern. ASTM standards:
Standard Practice for Design and Installation of Ground Water Monitoring Wells in Aquifers (D 5092-02);
Standard Guide for Decommissioning of Ground Water Wells, Vadose Zone Monitoring Devices, Boreholes, and Other
Devices for Environmental Activities (D 5299-99);
Standard Guide for Installation of Direct Push Ground Water Monitoring Wells (D 6724-01); and
Standard Practice for Direct Push Installation of Prepacked Screen Monitoring Wells in Unconsolidated Aquifers (D
6725-01).
2. Applicability:
2.1 The construction standards in this Appendix apply to monitoring wells installed pursuant to these Rules. The
construction standards shall not apply to drinking water wells or other subsurface borings that are used for purposes
other than monitoring groundwater quality.
2.2 The abandonment procedures in this Appendix apply to monitoring wells, piezometers and other subsurface
borings that intersect the seasonal water table at some time of the year.
3.
Prevention of Groundwater Pollution: During well construction and abandonment, every appropriate precaution shall be
taken to prevent introducing pollutants into the groundwater. This shall include, but not be limited to, steam cleaning and
washing of drilling equipment and proper cleaning and storage of well casing. Only unpolluted water shall be used in well
construction and abandonment unless otherwise approved by the Director.
4.
Deviation from the Standards: The Director may waive the requirements and allow deviation from these procedures
where such deviations will result in procurement of representative groundwater samples or, in the case of well abandonment,
will not result in a reasonable potential for groundwater pollution. All deviations from the procedures shall be documented
and provided to the Director for approval prior to well installation or abandonment. If the Director determines that the
deviation from these procedures will not or does not result in the procurement of samples representative of groundwater, the
Director may require alternative procedures or the installation of a new monitoring well.
5. Drilled Wells: Monitoring wells constructed using conventional drilling methods shall be installed in accordance with the
requirements below (see Figure A1-1). Monitoring wells completed into bedrock without a well screen (open bore hole) are
exempt from the requirements of Rules 5.3, 5.4 and 5.5.1, but must comply with all other requirements in Rule 5. Bedrock
monitoring wells shall have a well casing extending a minimum of 5 feet into the bedrock.
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5.1 Borehole Diameter: The borehole diameter in the overburden shall be a minimum of 4 inches greater than the
diameter of the well casing.
5.2 Well Casing (or Riser): The well casing shall be constructed of PVC material. Monitoring wells less than 100 feet
in depth shall be constructed using a minimum of schedule 40 PVC. Wells greater than 100 feet deep shall be
constructed using a minimum of schedule 80 PVC. The Director may allow alternate well casing material if the pollutant
concentrations or geologic setting require an alternative construction. Alternative materials include, but are not limited
to: Teflon, stainless steel, or uncoated or galvanized steel.
5.2.1 Assembly and Installation: All casing shall be constructed of flush threaded joints or threaded coupling
joints. All joints shall be fitted with an "O" ring or wrapped with teflon tape. Glued or solvent welded joints are
not permissible without prior written permission of the Director.
5.2.2 Cap: The well casing shall be fitted with a plug or cap.
5.3 Well Screen: The well screen slot size shall retain at least 90% of the grain size of the filter pack or at least 90% of
the grain size of the collapsed formation when no filter pack is used in accordance with Rule 5.4. Well screens shall not
exceed the length necessary to collect a representative groundwater sample. Well screens shall be factory slotted or
continuous wrapped wire-wound. A bottom cap and sump sediment trap shall be installed.
5.4 Filter Pack: The filter pack shall be clean, chemically inert, well rounded and well sorted glass beads or silica-based
sand or gravel of uniform grain size. The filter pack must minimize the amount of fine material entering the well and
shall not inhibit the flow of water or movement of pollutants into the well. The filter pack shall be installed by bottom-
up tremie methods. The filter pack shall extend from 6 inches beneath the bottom of the well screen to a distance above
the well screen equivalent to 20% of the well screen but not less than 2 feet. A collapsed formation may be used as the
filter pack if the well screen retention requirement of Rule 5.3 is met and a filter pack can not be installed.
5.5 Sealing Requirements
5.5.1 Filter Pack Seal: All monitoring wells installed with a filter pack shall be constructed with a filter pack seal
of bentonite pellets or slurry in a manner that does not disturb the filter pack. The seal shall extend to
approximately 3 to 5 feet above the filter pack and shall be properly hydrated and set.
5.5.2 Annular Space Seal: All monitoring wells shall be installed with an annular space seal using neat cement,
neat cement-bentonite mixture, bentonite slurry or bentonite that is properly hydrated and set. Granular bentonite
in dry form or powdered bentonite in dry form shall not be used in the saturated zone. The annular space seal shall
extend to the ground surface seal, except where a road box meeting the requirements of Rule 5.7 of this Appendix
is used.
5.5.3 Ground Surface Seal: All monitoring wells shall be constructed with a continuous pour concrete ground
surface seal. To avoid frost heaving and to anchor the well, the ground surface seal shall extend to a minimum of
40 inches below the land surface, unless the seal would interfere with proper placement or functioning of the well
screen or a road box is installed in accordance with Rule 5.7. The ground surface seal shall be flared such that the
diameter at the top is greater than the diameter at the bottom. The top of the ground surface seal shall be sloped
away from the well casing and shall be large enough to allow drainage away from the well.
Groundwater Quality Rules, June 2010
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5.6 Protective Casing: The protective casing shall consist of a minimum 4 inch diameter metal casing with locking
cap. The protective casing shall extend from the bottom of the ground surface seal to a minimum of 24 inches above the
land surface, allowing for 4 to 6 inches clearance between the top of the well casing and the cap of the protective casing.
A ¼ inch diameter drain hole shall be drilled into the protective casing 6 inches above the ground level. Dry bentonite
pellets, granules or chips shall then be placed in the annular space below ground level within the protective casing.
Coarse sand or washed pea gravel or both shall be placed above the dry bentonite to a depth covering the drain hole. A
high visibility guard post may be required. The Director may request additional protective devices as necessary.
5.7 Road Box: Road boxes are acceptable in locations where protective casings installed in accordance with Rule 5.6
are not suitable. All road boxes shall be secured and water tight and shall prevent easy access to the well. The well
casing shall be fitted with a locking, watertight cap. The ground surface seal for the road box shall be competent such
that vehicle traffic will not cause it to fail. The annular space seal shall extend upward to one foot below the ground
surface seal. Permeable material shall be emplaced between the ground surface seal and the annular space seal in order
to allow for the drainage of runoff which may leak into the road box from the ground surface. The road box cover plate
shall clearly indicate that the well is a groundwater monitoring well.
5.8 Well Development: Development of all monitoring wells shall be performed no earlier than 24 hours after
completion and before the initial water quality samples are taken. Well development shall continue until the water has
stable pH, temperature, and specific conductivity readings and has turbidity values less than 5 NTUs (nephelometric
turbidity units). If a well does not meet the goal of 5 NTUs, it must be demonstrated to the satisfaction of the Director
that proper well completion and well development have been employed. Groundwater sampling shall not occur until at
least 24 hours after well development, in order to allow natural groundwater flow to be re-established.
5.9 Monitoring Well Designation: Each monitoring well shall be clearly and permanently labeled as a monitoring well
with the well number using such techniques as etching in the protective casing or in the cement of the ground surface
seal.
6. Single Rod Direct Push Wells: Wells installed using single rod direct push methods shall be installed in accordance with
the requirements below:
6.1 Annular space seal -- If the screen and riser are of the same diameter and are advanced such that they remain in
contact with the formation during installation (exposed screen wells) no annular space seal is created. If the drive rod is
smaller in diameter than the sampler body (protected screen wells) an annular space is created that must be sealed in
accordance with Rule 5.5.2 above;
6.2 Ground surface seal shall be constructed in accordance with Rule 5.5.3;
6.3 Protective casing or road box shall be installed in accordance with Rule 5.6 or Rule 5.7, respectively. In order to
provide a locking, water-tight cap on a small diameter well casing in a road box as required by Rule 5.7, a 2 inch PVC
casing can be placed over the well riser extending 3 to 4 feet below grade;
6.4 Well must be developed in accordance with Rule 5.8; and
6.5 Well shall be properly designated in accordance with Rule 5.9.
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7. Two-tube Direct Push Wells: Monitoring wells installed using two-tube direct push methods create an annular space the
length of the well, thus requiring a filter pack, seals and other provisions similar to conventional drilled wells. Two-tube
direct push wells shall be installed in accordance with the requirements below (see Figure A1-2):
7.1 The outside diameter of the borehole shall be a minimum of one inch greater than the outside diameter of the well
casing;
7.2 Well casing (or riser) shall meet the requirements of Rule 5.2;
7.3 Well screen shall meet the requirements of Rule 5.3;
7.4 Filter Pack: The filter pack shall be clean, chemically inert, well rounded and well sorted glass beads or silica-based
sand or gravel of uniform grain size. The filter pack must minimize the amount of fine material entering the well and
shall not inhibit the flow of water into the well. The filter pack shall be installed by bottom-up tremie methods, or it can
be a pre-packed manufactured unit. A collapsed formation may be used as the filter pack if the well screen retention
requirement of Rule 5.3 is met and a filter pack can not be installed.
7.5 Grout Barrier: All direct push monitoring wells installed with a filter pack shall be constructed with a grout barrier
immediately above the screened interval to prevent annular space sealants from entering the screened interval. The grout
barrier shall extend a minimum of 2 feet above the screened interval. The grout barrier may be constructed by gravity or
tremie installation of fine sand, or by installation of a modular system. Alternatively, collapse of the natural formation
may be used to create a natural barrier when the formation material is of appropriate grain size and cohesion.
7.6 Filter pack seal shall be constructed in accordance with Rule 5.5.1;
7.7 The annular space shall be sealed in accordance with Rule 5.5.2 or a modular system may be used;
7.8 Ground surface seal shall be constructed in accordance with Rule 5.5.3 ;
7.9 Protective casing or road box shall be installed in accordance with Rule 5.6 or Rule 5.7 , respectively;
7.10 Well must be developed in accordance with Rule 5.8; and
7.11 Well shall be properly designated in accordance with Rule 5.9.
8. Abandonment of Monitoring Wells, Piezometers and Other Subsurface Borings
8.1 Monitoring wells, piezometers and other subsurface borings shall be abandoned in accordance with this Rule or
alternate procedures approved in writing by the Director prior to abandonment. Abandonment shall take place within 60
days after use has been terminated or within a timeframe approved by the Director.
8.2 Abandonment Procedures for Monitoring Wells and Borings Constructed with an Annular Space:
8.2.1 The borehole shall be inspected from the land surface through its entire depth before it is sealed, to ensure
against the presence of any obstructions that will interfere with sealing operations.
8.2.2 The casing shall be removed by pulling or overdrilling. If the casing can not be removed, the screen and
Groundwater Quality Rules, June 2010
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casing shall be suitably perforated from top to bottom allowing for the plugging material (see Rule 8.2.3) to
penetrate the annular space and formation. If the casing remains, it shall be cut off at least 4 feet below the ground
surface where practicable.
8.2.3 The remaining casing or borehole shall be filled with neat cement or neat cement grout applied under
pressure.
8.3 Abandonment Procedures for Monitoring Wells and Borings Constructed without an Annular Space:
8.3.1 The borehole shall be inspected from the land surface through its entire depth before it is sealed, to ensure
against the presence of any obstructions that will interfere with sealing operations.
8.3.2 If the casing is to be removed, the remaining borehole shall be filled with neat cement or neat cement grout
applied under pressure.
8.3.3 If the casing remains in the ground, it shall be cut off at least 4 feet below the ground surface. The remaining
casing shall be filled with neat cement or neat cement grout applied by bottom-up tremie methods.
Groundwater Quality Rules, June 2010
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Locking Cap
Secure Plug or Cap
Protective
Casing
Ground Surface
Filter Pack Seal
Annular Space
Seal
Borehole Wall
Well Screen
Filter Pack
Bottom Cap and
Sediment Sump
Well Casing
Ground Surface Seal
Dry Bentonite
Coarse Sand or
Washed Pea Gravel
Weep Hole
Figure A1-1. Drilled Monitoring Well in Overburden with Protective Casing (not to scale)
Groundwater Quality Rules, June 2010
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Grout Barrier
Well Casing
Filter Pack
Seal
Annular Space
Seal
Pre-packed Well Screen
Permeable Material
Locking Water Tight Cap
Secured Water Tight Cover
Ground Surface Seal
Drive Point
Ground Surface
Borehole Wall
Figure A1-2. Two-tube Direct Push Monitoring Well with Road Box (not to scale)
Groundwater Quality Rules, June 2010
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APPENDIX 2
Groundwater Classification Map
(8.5" x 11")
Note:
This is an unofficial map of the groundwater classifications. The official delineations were done
using the United States Geological Survey 7.5 minute quadrangle maps (1:24,000 scale). These
delineations are on file at the Rhode Island Department of Environmental Management, 235
Promenade Street, Providence, RI 02908 and available on the Department’s website at
www.dem.ri.gov.
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Groundwater Quality Rules, June 2010
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APPENDIX 3
Map of Groundwater Reservoirs and
the Critical Portions of Their Recharge Areas
(8.5" x 11")
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Groundwater Quality Rules, June 2010
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APPENDIX 4
Wellhead Protection Area Map
(8.5" x 11")
Note:
This is an unofficial map of the wellhead protection areas. The official wellhead protection area
delineations were done using the United States Geological Survey 7.5 minute quadrangle maps
(1:24,000 scale). These delineations are on file at the Rhode Island Department of Environmental
Management, 235 Promenade Street, Providence, RI 02908 and available on the Department’s
website at www.dem.ri.gov.
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Groundwater Quality Rules, June 2010
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APPENDIX 5
WELLHEAD PROTECTION AREA
DELINEATION METHODOLOGY
Introduction
A wellhead protection area (WHPA) is the portion of an aquifer through which groundwater moves to a
well. Under the Rhode Island Department of Environmental Management (DEM) Wellhead Protection
(WHP) Program approved by the US Environmental Protection Agency in 1990, DEM is responsible for
delineating a WHPA for each of the public wells in the state. This document will provide a description of
the methodology used for the WHPA delineations. WHPA maps are available for review at the DEM
Office of Water Resources and on the DEM website.
The DEM methodology was used to delineate the WHPAs for all of the public wells when the WHPA
map was first adopted in the 1993 amendments to the Groundwater Quality Rules and for new public
wells that came on line in the 1990s and early 2000s. Most of the new community water supply wells
installed in stratified drift over approximately the last five years have WHPAs that meet the definition of
a refined WHPA. A refined WHPA is a more advanced delineation based on more complex
methodologies (see discussion at end of this document).
DEM relied on technical input from the Wellhead Protection Program Advisory Committee in developing
the delineation methodology in the late 1980s. A mapping approach was required that was scientifically
defensible, could be applied consistently across the state, and could be applied with the resources
available to DEM. The delineations are based on reasonably available information regarding the
hydrogeologic environment and the well characteristics. The method does not provide the level of detail
necessary to account for potential well interference. The WHPAs were delineated using the US
Geological Survey quadrangle maps at a scale of 1:24000.
The WHPA delineation methodology differs depending if the well is completed in bedrock or stratified
drift. The WHPA for bedrock wells is a circle with the radius dependent on the well’s pump rate. The
WHPA for stratified drift wells is a curve in the stratified drift generated by an analytical model with
hydrogeologic/topographic mapping in the upgradient till. To a lesser extent, the methodology varies
depending on the type of public well, i.e., community, non-transient non-community or transient non-
community (see public well definition at end of this document). The methodologies are described in more
detail below.
Bedrock Wells
Groundwater flow direction in bedrock is extremely difficult to predict without a site-specific study.
Since the groundwater flow direction for these wells is unknown, the WHPA is a circle (size is
determined by the pump rate) in order to be certain to include areas upgradient of the well. The Theis
analytical model was used to delineate the WHPA for all bedrock public wells (community, non-transient
non-community and transient non-community). The input parameters for the Theis equation were the
same for each well, except for the pump rate. If the pump rate was unknown or less than 10 gallons per
Groundwater Quality Rules, June 2010
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minute, a 10 gallon per minute pump rate was used resulting in a minimum WHPA with a radius of 1750
feet. The following table provides the calculated radius for selected pump rates:
Wellhead Protection Area Radius for Bedrock Wells
Pumping Rate
Radius
Pumping Rate
Radius
(gpm)
(ft)
(gpm)
(ft)
≤10
1750
23
2411
11
1820
24
2440
12
1872
25
2466
13
1920
30
2568
14
1965
35
2638
15
2008
40
2689
16
2087
45
2729
17
2153
50
2760
18
2211
60
2806
19
2261
70
2875
20
2305
80
2985
21
2344
90
3068
22
2380
100
3133
The Theis model can be expressed as follows:
)
(
6.
114
u
W
T
Q
s =
Tt
S
r
u
2
87
.1
=
Where: s = drawdown; 1 foot
Q = well pumping rate
T = transmissivity; 374 gpd/ft
S = storage coefficient; .01 (dimensionless)
t = time; 200 days
W(u) = well function (dimensionless)
r = distance from pumped well
114.6 and 1.87 are coefficients generated for conversion from metric to english units
and conducting some simplifying calculations
Note: The original delineation methodology for bedrock wells with a pump rate greater than 10 gpm also
included areas beyond the Theis generated circle where groundwater in the overburden flowed into the
circle. This aspect of the methodology was re-evaluated in early 2002, and it was concluded that it was
inappropriate to include the area beyond the circle in the WHPA delineation. As a result, all bedrock
WHPAs delineated by DEM are in the shape of a circle.
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Stratified Drift Wells
The WHPA for community and non-transient non-community stratified drift wells was determined by
solving the uniform flow equation (UFE) analytical model for the delineation in the stratified drift and by
using hydrogeologic mapping in the upgradient till deposits. Site specific input parameters for each well
were used in solving the UFE, which can be expressed as follows:
Y
Q
Kbi
X
Y
π
2
tan
=
−
Kbi
π
2
Q
X L
−
=
Kbi
2
Q
YL
±
=
Where: Q = well pumping rate (ft3/day)
K = hydraulic conductivity (ft/day
b = saturated thickness (ft)
Note: K x b = Transmissivity
i = hydraulic gradient (dimensionless)
XL = distance to downgradient null point (ft)
YL = distance to lateral boundary limit (ft)
X,Y = cartesian coordinates of points along the groundwater divide
The UFE was solved with the MWCAP module of the US EPA WHPA model software package. The
downgradient null point, XL, is the location on the UFE curve that represents the distance from which a
well is pulling groundwater toward itself that would otherwise flow away from the well. As the UFE
curve widens on both sides of the well upgradient, it asymptotically approaches the lateral boundary
limits of groundwater flow, which are defined by ± YL.
Depending upon the well’s hydrogeologic setting, the UFE curve was extended upgradient as far as one
of the following: a groundwater divide, the till/stratified drift boundary, or the ten-year time of travel
distance from the well. The WHPA was defined by the UFE curve when the curve was terminated by a
groundwater divide or the ten-year time of travel distance. However, in most cases, the till/stratified drift
boundary was used as the upgradient limit of the UFE curve. In these instances, The WHPA also
included the upgradient till areas through which groundwater flows to the curve as determined by water
table information or topography (most cases topography).
In solving the UFE, only one value for K, b, and i can be used, and these values should be representative
of the entire area of stratified drift that is to be captured by the UFE curve. Published US Geological
Survey mapped data was used to determine the average transmissivity (saturated thickness times
hydraulic conductivity equals transmissivity) and hydraulic gradient. These average values were
calculated over an area referred to as a “clip box” using geographic information system software. The
clip box is a mathematically determined estimate of the WHPA in the stratified drift. Where published
data was not available, transmissivity was determined from pump tests, lithologic logs, or specific
capacity data, and the hydraulic gradient was measured manually.
Groundwater Quality Rules, June 2010
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As new community and non-transient non-community stratified drift wells come into service, an interim
WHPA defined by a circle with a 2000 foot radius is assigned until DEM provides a delineation in
accordance with the above methodology or the water supplier provides DEM with an acceptable
delineation.
Other Wells
There are several instances that do not fit into the two categories above. These situations apply to a small
number of wells, most of which serve transient systems. Wells in the following categories have a circular
WHPA with a radius of 1750 feet:
- The geologic formation supplying water to the well is unknown;
- Springs;
- Wells completed in till; and
- Transient non-community wells completed in stratified drift.
Refined WHPAs
The WHPAs delineated by DEM have provided a suitable basis for state and local protection efforts.
When the DEM methodology was developed in the late 1980s, it was anticipated that in the future more
site specific data or more complex methods would be used to revise the DEM provided WHPAs or to map
the WHPA for new wells. As of June 1, 2010, 45 wells have a WHPA that was delineated using a more
advanced approach (refined WHPA) than the standard DEM methodology. DEM reviews the results of
each model used by a supplier or other state or federal agency to determine the area to be designated as
the WHPA. The Rhode Island Department of Health has been using funds from the Safe Drinking Water
Act for the US Geological Survey to delineate refined WHPAs for selected existing DEM WHPAs, which
DEM then incorporates into the WHPA map.
Public Well Definitions:
Community Well – serves year-round residents; at least 15 service connections or at least 25 individuals.
Examples include municipal wells and wells serving nursing homes, condominiums, and mobile home
parks.
Non-Transient Non-Community Well – regularly serves at least 25 of the same persons (not residents)
over 6 months of the year. Examples include wells serving schools and places of employment.
Transient Non-Community Well – does not regularly serve the same persons, but does serve at least 25
people at least 60 days of the year. Examples include wells serving restaurants and motels.
_______________________________________________________
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RULE 24. EFFECTIVE DATE
The foregoing “Groundwater Quality Rules after due notice, are hereby adopted and filed with the Secretary
of State this ____________ day of ____________________ 2010 to become effective twenty (20) days
thereafter, in accordance with the provisions of Chapters 42-35, 42-17.1, 42-17.6, 46-12, 46-13.1, 23-18.9,
and 23-19.1 of the General Laws of Rhode Island, 1956, as amended.
______________________________________________________
W. Michael Sullivan, Ph.D.
Director, Department of Environmental Management
Notice Given On:
April 26, 2010
Public Hearing Held:
Not requested
Filing Date:
Effective Date: