Distribution

Distribution. 1. Drip Tubing: a. The drip tubing may be installed using any of the following methods: i. Excavation by a trenching machine. ii. Approved plowing method as determined by the tubing manufacturer. The insertion tool must be of the type that does not pull or stretch the drip line during insertion. The use of “cable plows” or any type insertion method that employs pulling the drip line through the plowed trench is prohibited. b. To ensure equal dosing of the field there can be no more than a 10 percent variance in the flow between any 2 emitters in the entire field. c. The length of each distribution line shall not exceed drip tubing manufacturer’s specifications to ensure equal distribution to each emitter. d. If necessary, pressure compensating devices or regulators shall ensure equal distribution from all emitters at +/− 10% of the designed discharge rate. e. Emitter outlet orifices are non-directional devices. 2. Pump Chambers: a. During normal operating procedures the inlet to the treatment system shall not become surcharged. b. The pump chamber shall have a minimum capacity of 1.5 times the estimated daily flow. c. The pump chamber shall be equipped with an audible high-water alarm and may utilize a functional self-opening relief valve. d. The pump chamber shall have a grade level access allowing a minimum of 17- inch diameter or 15-inch square, to allow servicing and/or removal of the largest component in the chamber. Access ports shall be protected against unauthorized entrance or removal, by use of tamper proof fasteners or a lid weighing 65 pounds or more. e. The pump chamber shall be vented through the grade level access or by means of a separate vent. In either case, the vent shall be a minimum of 1 inch in diameter. f. The pump chamber shall be made of material resistant to the corrosive effects of wastewater and designed to withstand the lateral and bearing loads to which it is expected to be subjected. g. All openings shall be sealed with mastic, butyl rubber or other pliable sealant that is waterproof, corrosion resistant and approved for use in contact with wastewater, in a manner to prevent the entrance of surface and groundwater. h. The high-water alarm must be set so as to allow a reserve capacity equal to ½ day estimated flow. 3. Minimum Pump Specifications: a. The pumping system shall be capable of dosing the disposal field a minimum of 6 equally spaced doses per 24 hour period. Each dose volume shall not exceed the estimated maximum daily flow divided by the number of dosing cycles. It is acceptable that daily usage of less than the design flow rate will result in a diminished number of cycles. An emergency override float is required to accommodate conditions which exceed the normal daily flow rate. [See Table 12.] b. The pumping system shall be designed to discharge the required volume of wastewater within the pressure range specified by all component manufacturers. c. The pump shall be equipped with a low water cutoff to prevent damage to the pump during low water conditions in the pump chamber. d. The pump shall be constructed of corrosion resistant materials suitable for effluent pumping. e. The pump shall be sized per pump and components manufacturers’ specifications to meet or exceed the hydraulic requirement of the system. f. The pump shall be installed so as not to violate the pump warranty. g. The suction and pressure lines shall be Schedule 40 or equal and be sized to meet or exceed the hydraulic requirements of the system. 4. Minimum Filter Specifications: a. The filter shall filter effluent to prevent clogging to the specifications of the drip tubing manufacturer. b. The filter shall achieve the required filtration at a rate equal to or greater than the peak discharge rate, including filter and/or system backwash. c. An independent third party, acceptable to the Division, shall certify the filter performance. Verification from a manufacturer of filters or by an independent registered Professional Engineer. d. The filter shall be made of material resistant to the corrosive effects of wastewater and common household chemicals. e. The filter shall be readily accessible for inspection, service and/or maintenance. f. The filter flush volume and velocity shall be per filter manufacturer’s specifications. g. The filter residue shall be returned to the treatment system. h. The Subsurface Drip Irrigation System must provide an automatic field flush to prevent the build-up of solids in the distribution system, with its discharge returning to the treatment system and be capable of achieving a flushing velocity of a minimum of 1 foot per second. The return line must be permanently installed as a component of the system. A hose bib shall be prohibited as a component. 5. Component Specifications: a. Vacuum breakers shall be installed as per drip tubing manufacturer’s specification, a minimum of 1 vacuum breaker/air release valve for each drip field zone. b. Vacuum breakers shall be located in a protective enclosure that will prevent the accumulation of any substance that would prevent their proper operation and shall have a grade level access. c. All materials shall meet applicable American Society for Testing and Materials (ASTM) standards and be resistant to common household chemicals. The drip tubing manufacturer must certify drip tubing as designed and manufactured for the disposal of wastewater. The drip tubing must be color coded, by the manufacturer, to be easily identified as tubing designed for wastewater disposal. d. Equipment susceptible to freezing must be adequately protected.