2010 Stormwater Management Report (PDF) - US Environmental ...

In 2010, the Commission approved 185 projects that included installation of dry wells or
other type of infiltration device. Table 3 – 4 provides the addresses of the devices
approved in 2010.
Controls for New Parking Lots: In order to prevent oil, grease and sediments from
discharging to open waterways, the Commission requires that developers install particle
separators on all newly constructed storm drains that serve outdoor paved areas of 7,500
square feet in size or greater. The Commission may require particle separators on
existing storm drains from existing outdoor parking areas, where appropriate. This
requirement has been in place since 1992.
Parking lot particle separators are typically located on private property; therefore, their
maintenance is the responsibility of the property owner. Design criteria for particle
separators are set forth in the Commission’s Guidelines for Developers for the
Installation, Operation and Maintenance of Grit and Oil Separators, a copy of which is
included in the Commission’s Requirements for Site Plans.
In 2010, the Commission approved installation of particle separators at 24 locations.
Table 3 – 5 provides the addresses of the devices approved in 2010.
Drainage Discharge Permits: The Commission requires a Drainage Discharge Permit
for all non-stormwater discharges to its drainage system, including construction site
dewatering, permanent subsurface drainage, non-contact cooling water, non-contact
industrial process water, and waters associated with hydrological testing, groundwater
treatment/remediation, and removal and installation of an underground storage tank. The
Commission may deny or condition a dewatering permit to prevent contaminated
drainage from entering the sewer or drainage system. Failure to obtain a Drainage
Discharge Permit carries a fine of up to $1,000 a day under the Commission’s Sewer Use
Regulations. In 2010, the Commission issued 7 Drainage Discharge Permits for
discharges to storm drains.
Infiltration/Inflow Control: Newly constructed and substantially renovated buildings
must be constructed so as to minimize inflow and infiltration to the Commission’s
wastewater system. Stormwater, including roof runoff, must be kept separate from
sanitary sewage at all times, and the connection of a building storm drain to a sanitary
sewer is prohibited.
For development projects requiring review under Massachusetts Environmental Policy
Act (MEPA) and that add a significant amount of new wastewater flow to the sewer
system, DEP currently requires a reduction of 4 units of infiltration or inflow for each
new unit of wastewater added. The Commission supports the DEP in this requirement.
Developers of large projects can propose their own I/I reduction measures and submit
them for review and approval by the Commission; they can select I/I reduction projects
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