Module 3 Footnotes
1 Calculated
from a decay rate table provided in Appendix 1 of Septic Tank Siting
to Minimize the Contamination of Ground Water by Microorganisms from
Office of Groundwater Protection, Washington, D.C., June, 1987.
2
Section 15.214: Nitrogen Loading Limitations
(1) No system serving new construction in Nitrogen Sensitive Areas designated
in 310 CMR 15.215 shall be designed to receive or shall receive more than
440 gallons of design flow per acre except as set forth at 310 CMR 15.216
(aggregate flows) or 15.217 (enhanced nitrogen removal).
(2) No system serving new construction in areas where the use of both on-site
systems and drinking water wells is proposed to serve the facility shall
be designed to receive or shall receive more than 440 gallons of design
flow per day per acre from residential uses except as set forth at 310
CMR 15.216 (aggregate flows) or 15.217 (enhanced nitrogen removal).
3
Actually leaching pits and deeper leaching structures are not prohibited
in the code, however since only two feet of the sidewall area can be used
for credit, they have essentially lost favor with most engineers and installers.
4
Note: Some old copies of the revised code contain an error in these
setback distances.
5
The Natural Heritage and Endangered Species Program, administered by
The Massachusetts Department of Wildlife creates yearly updated maps for
each area that depict vernal pools. Conservation Commissions maintain the
maps in their offices for public viewing. The program can be contacted
at Rte 135, Westborough, MA 01581.
6 Section
15.211[2} states "The required setback shall be 50 feet where the
applicant has provided hydrogeologic data acceptable to the approving authority
demonstrating that the location of the soil absorption system is hydraulically
downgradient of the vernal pool. Surface topography alone is not determinative".
7 Section
15.405: Contents of Local Upgrade Approval (1)(h) Reduction of system
location setbacks from water supply lines, private water supply wells (but
not within 50 feet of the well),.....
8 There is
a minimum Zone 1 of 100 ft.
9 15.212.
Depth to Groundwater The minimum vertical separation distance of the
bottom of the stone underlying the soil absorption system above the high
ground-water elevation shall be (a) four feet in soils with a recorded
percolation rate of more than two minutes per inch; (b) five feet in soils
with a recorded percolation rate of two minutes or less per inch.
10
(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.