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Storm Sewers:
PROTECTING WATER QUALITY FROM URBAN RUNOFF. CLEAN WATER IS EVERYBODY’S
BUSINESS.
In urban and suburban areas, much of the land surface is covered by
buildings and pavement, which do not allow rain and snowmelt to soak
into the ground. Instead, most developed areas rely on storm drains to
carry large amounts of runoff from roofs and paved areas to nearby
waterways. The storm water runoff carries pollutants such as oil, dirt,
and lawn fertilizers directly to streams and rivers, where they
seriously harm water quality. To protect surface water quality and
groundwater resources, development should be designed and built to
minimize increases in runoff.
EPA
United States
Environmental Protection Agency
EPA 841-F-03-003
The most recent National – Water Quality Inventory reports that runoff
from urbanized areas is the leading source of water quality impairments
to surveyed estuaries and the third-largest source of impairments to
surveyed lakes.
Did you know that because of impervious surfaces like pavement and
rooftops, a typical city block generates more than 5 times more runoff
than a woodland area of the same size?
HOW URBANIZED AREAS AFFECT WATER QUALITY
Increased Runoff
The porous and varied terrain of natural landscapes like forests,
wetlands, and grasslands traps rainwater and snowmelt and allows them to
filter slowly into the ground. In contrast, impervious (nonporous)
surfaces like roads, parking lots, and rooftops prevent snowmelt from
infiltrating, or soaking, into the ground. Most of the rainfall and
snowmelt remains above the surface, where it runs off rapidly in
unnaturally large amounts.
Storm sewer systems concentrate runoff into smooth, straight conduits.
This runoff gathers speed and erosion power as it travels underground.
When this runoff leaves the storm drains and empties into a stream, its
excessive volume and power blast out stream banks, damaging streamside
vegetation and wiping out aquatic habitat. These increased storm flows
carry sediment loads from construction sites and other denuded surfaces
and eroded stream banks. They often carry higher water temperatures from
streets, rooftops, and parking lots, which are harmful to the health and
reproduction of aquatic life.
The loss of infiltration from urbanization may also cause profound
groundwater changes. Although urbanization leads to great increases in
flooding during and immediately after wet weather, in many instances it
results in lower stream flows during dry weather. Many native fish and
other aquatic life cannot survive when these conditions prevail.
Increased Pollutant Loads
Urbanization increases the variety and amount of pollutants carried into
streams, rivers, and lakes. The pollutants include:
Sediment
Oil, grease, and toxic chemicals from motor vehicles
Pesticides and nutrients from lawns and gardens
Viruses, bacteria, and nutrients from pet waste and failing septic
systems
Road salts
Heavy metals from roof shingles, motor vehicles, and other sources
Thermal pollution from dark impervious surfaces such as streets and
rooftops
These pollutants can harm fish and wildlife populations, kill native
vegetation, foul drinking water supplies, and make recreational area
unsafe and unpleasant.
Relationships between impervious cover and surface runoff: Impervious
cover in a watershed results in increased surface runoff. As little as
10 percent impervious cover in a watershed can result in stream
degradation.
Managing Urban Runoff
What Homeowners Can Do:
To decrease polluted runoff from paved surfaces, households can develop
alternatives to areas traditionally covered by impervious surfaces.
Porous pavement materials are available for driveways and sidewalks, and
native vegetation and mulch can replace high maintenance grass lawns.
Homeowners can use fertilizers sparingly and sweep driveways, sidewalks,
and roads instead of using a hose. Instead of disposing of yard waste,
they can use materials to start a compost pile. Homeowners can learn to
use integrated Pest Management. (IMP) to reduce dependence on harmful
pesticides
In addition, households can prevent polluted runoff by picking up after
pets and using, storing, and disposing of chemicals properly. Drivers
should check their cars for leaks and recycle their motor oil and
antifreeze when these fluids are changed. Drivers can also avoid impacts
from car wash runoff (e.g. detergents, grime, etc.) by using car wash
facilities that that do not generate runoff. Households served by septic
systems should have them professionally inspected and pumped every 3 to
5 years. They should also practice water conservation measures to extend
the life of their septic systems.
Controlling Impacts from New Development
Developers and city planners should attempt to control the volume of
runoff from new development by using low impact development, structural
controls, and pollution prevention strategies. Low impact development
includes measures that conserve natural areas (particularly sensitive
hydrologic areas like riparian buffers and infiltrate soils); reduce
development impacts; and reduce site runoff rates by maximizing surface
roughness, infiltration opportunities, and flow paths.
Controlling Impacts from Existing
Development
Controlling runoff from existing urban areas is often more costly than
controlling runoff from new developments. Economic efficiencies are
often realized through approaches that target “hot spots” of runoff
pollution or have multiple benefits, such as high-efficiency street
sweeping (which addresses aesthetics, road safety, and water quality).
Urban planners and others responsible for managing urban and suburban
areas can first identify and implement pollution prevention strategies
and examine source control opportunities. They should seek out priority
pollutant opportunities, protect natural areas that help control runoff,
and finally begin ecological restoration and retrofit activities to
clean up degraded water bodies. Local governments are encouraged to take
lead roles in public education efforts through public signage, storm
drain marking, pollution prevention outreach campaigns, and partnerships
with citizen groups and businesses. Citizens can help prioritize the
clean-up strategies, volunteer to become involved in restoration
efforts, and mark storm drains with approved “don’t dump” messages.
Related Publications
Turn Your Home into a Storm water Pollution Solution! www.epa.gov/nps
This website links to an EPA homeowner’s guide to healthy habits for
clean water that provides tips for better vehicle and garage care, lawn
and garden techniques, home improvement, pet care, and more.
National Management Measures to Control Non-point Source Pollution from
Urban Areas www.epa.gov/owow/nps/urbanmm
This technical guidance and reference document is useful to local,
state, and tribal managers in implementing management programs for
polluted runoff. It contains information on the best available,
economically achievable means of reducing pollution of surface waters
and groundwater from urban areas.
Onsite Wastewater Treatment System Resources www.epa.gov/owm/onsite
This website contains the latest brochures and other resources from EPA
for managing onsite wastewater treatment systems (OWTS) such as
conventional septic systems and alternative decentralized systems. These
resources provide basic information to help individual homeowners, as
well as detailed, up-to-date technical guidance of interest to local and
state health departments.
Low Impact Development Center www.lowimpactdevelopment.org
This center provides information on protecting the environment and water
resources through integrated site design techniques that are intended to
replicate preexisting hydrologic site conditions.
Storm water Manager’s Resource Center (SMRC) www.stormwatercenter.net
Created and maintained by the Center for Watershed Protection, this
resource center is designed specifically for storm water practitioners,
local government officials, and others that need technical assistance on
storm water management issues.
Strategies: Community Responses to Runoff Pollution www.nrdc.org/water/pollution/storm/stoinx.asp
The Natural Resources Defense Council developed this interactive web
document to explore some of the most effective strategies that
communities are using around the nation to control urban runoff
pollution. The document is also available in print form and as an
interactive CD-ROM.
For More Information
U.S. Environmental Protection Agency
Non-point Source Control Branch (4503T)
1200 Pennsylvania Avenue, NW
Washington, DC 20460
www.epa.gov/nps
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CITY OF BURBANK
STORM WATER MANAGEMENT PROGRAM
I.E.P.A MS4 Annual Facility Inspection Reports 2020
1.
I.E.P.A Document
2. I.E.P.A
Permit
3. I.E.P.A Renewal |