310 CMR 15.213
Construction in Velocity Zones and Floodways
(1) No septic tank or humus/composting toilet shall be constructed in a velocity zone on a
coastal beach, barrier beach, or dune, or in a regulatory floodway, except a septic tank that
replaces a tank in existence on the site as of March 31, 1995 that has been damaged, removed
or destroyed, where placement of the tank outside of the velocity zone or regulatory floodway,
either horizontally or vertically, is not feasible. Where reconstruction of a system in existence
on March 31, 1995 occurs or reconstruction of a building or buildings is allowed in accordance
with the Wetlands Protection Act and 310 CMR 10.00: Wetlands Protection, it shall be
presumed to be feasible to elevate the tank if the building is elevated above the velocity zone or
regulatory floodway.
(2) No soil absorption system shall be constructed in a velocity zone on a coastal beach, barrier
beach, or dune, or in a regulatory floodway, unless
(a) the system is to serve a building or buildings that were in existence on March 31, 1995
or reconstruction of such building or buildings where allowed in accordance with the
Wetlands Protection Act, M.G.L. c. 140, § 131 and its implementing regulations as 310 CMR
10.00: Wetlands Protection;
(b) there is no increase in design flow from such building or buildings;
(c) no connection to a public sewer or shared system is available;
(d) the owner or applicant cannot site the system elsewhere;
(e) the septic tank or humus/composting toilet is sited outside of the velocity zone or
regulatory floodway, either horizontally or vertically;
(f) the system achieves separation from high groundwater elevation as required by
310 CMR 15.212; and
(g) any portion of the soil absorption system that is within the velocity zone or regulatory
floodway is a leaching bed or trench system or any other system constructed in accordance
with the Wetlands Protection Act and 310 CMR 10.00: Wetlands Protection.