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example, an infiltration trench must provide a minimum level of pollutant removal
as well as meet other performance requirements. A number of regulators are
specifically encouraging the use of LID techniques and other innovative
stormwater management solutions that reduce pollution associated with runoff.
Many already encourage the use of bioretention, dry wells (where permitted),
filter strips, vegetated buffers, grassed swales, and infiltration trenches. In some
cases, stormwater credits may be given for using LID approaches.
3-3.1.6 Section 404. Regulation of Dredged or Fill Material. Section 404 of the
CWA establishes programs to regulate the discharge of dredged or fill material into U.S.
waters, including wetlands. The U.S. Army Corps of Engineers and the EPA jointly
administer Section 404. According to these regulations,5 no discharge of dredged or fill
material can be permitted if a practicable alternative exists that is less damaging to the
aquatic environment, or if the nation's waters would be significantly degraded. In other
words, a permit applicant must demonstrate that they have:
taken steps to avoid wetland impacts where practicable;
minimized potential impacts to wetlands; and
provided compensation for any remaining, unavoidable impacts through
activities to restore or create wetlands.
LID features can reduce potential impacts to wetlands in several ways. First,
filtering out pollutants from runoff helps to preserve the quality of water reaching the
wetlands. Additionally, enhancing infiltration in the vicinity of the wetlands helps to
sustain the supply of groundwater that feeds them. Finally, by reducing runoff energy,
LID devices help prevent downstream erosion, reducing the volume of material that
must ultimately be dredged from a channel or reservoir.
Safe Drinking Water Act Wellhead Protection Program. The Wellhead
Protection Program protects the recharge areas of public water system wells from all
increase rates of infiltration. Care should be taken, however, to ensure that any
pollutants contained in runoff are adequately filtered out before the stormwater
percolates down to aquifers in wellhead protection zones.
Coastal Zone Management Act. The Coastal Zone Management Act
requires DoD facilities located in coastal states with approved coastal zone
management programs to conform to the state program. As part of their programs,
states must develop and implement coastal non-point source pollution control programs.
States may object to permits for activities that are inconsistent with the state's coastal
zone management plan. LID techniques can comprise a constructive response to state
implementation of a non-point source pollution control program.