|
|
Follow the links below to
find the subcategory of interest.
|
With
approximately 80 percent of the nation’s population
living in coastal areas, controlling polluted runoff
in urban areas is a challenge. Major pollutants found in runoff from urban areas include
sediment, nutrients, oxygen-demanding substances, road salts,
heavy metals, petroleum hydrocarbons, pathogenic bacteria,
viruses, trash, and plastics. Suspended sediments constitute
the largest mass of pollutant loadings to receiving waters
from urban areas , and construction is a major source of
sediment erosion. Petroleum hydrocarbons result mostly from
automobile sources. Nutrient and bacterial sources include
garden fertilizers, leaves, grass clippings, pet wastes,
and faulty septic tanks. As population densities increase,
a corresponding increase occurs in pollutant loadings generated
from human activities. Many of these pollutants enter surface
waters via runoff without undergoing treatment.
California ’s 15 urban management
measures address the prevention and treatment of NPS pollution
l during all phases of urbanization. Opportunities to control
NPS pollution occur during all three stages of development
: (1) the siting and design phase, (2) the construction phase,
and (3) the post-development phase. The control of urban
nonpoint source (NPS) pollution requires the use of two primary
strategies: the prevention of pollutant loadings and the
treatment of unavoidable loadings. This strategy relies primarily
on the watershed approach, which focuses on pollution prevention
or source reduction practices. Pollution prevention and source
reduction practices are favored over treatment practices
because conducting education practices and incorporating
pollution prevention practices into project planning and
design activities are generally more effective, require less
maintenance, and are more cost-effective in the long term
than treatment strategies. Treatment strategies should be
used only to address unavoidable loadings or where they are
truly cost-effective.
|
Please
see the California Nonpoint Source Encyclopedia for a fact
sheet on each of the management measures, containing
a description of related state and federal programs, a
list of specific management practices, additional information
resources, example case studies in California, and references.
|
 Runoff from Developing Areas 3.1A Watershed Protection. Develop
a watershed protection program to:
- Avoid conversion of areas that are particularly susceptible to erosion and sediment loss;
- Preserve areas that provide important water quality benefits and/or are necessary to maintain riparian and aquatic biota;
- Protect the natural integrity of water bodies and natural drainage systems associated with site development;
- Limit increases of impervious surfaces; and
- Provide education and outreach to address sources of NPS pollution.
3.1B Site Development. Plan, design,
and develop sites to:
- Protect areas that provide important water quality benefits necessary to main riparian and aquatic biota, and/or are particularly susceptible to erosion and sediment loss;
- Limit increases of impervious areas;
- Limit land disturbance activities such as clearing and grading, and cut-and-fill to reduce erosion and sediment loss; and
- Limit disturbance of natural drainage features and vegetation.
3.1C New Development. After construction
has been completed and the site is permanently stabilized,
reduce the average annual total suspended solids (TSS)
loadings by 80 percent, or reduce the post-development
loadings of TSS so that the average annual TSS loadings
are no greater than pre-development loadings. Also,
to the extent practicable, maintain post-development
peak runoff rate and average volume at levels that
are similar to pre-development levels. |
.: top of page
|
 Runoff from Construction Sites 3.2A Construction Site Erosion and Sediment
Control. Reduce erosion and, to the extent
practicable, retain sediment on site during and after
construction. Also, prepare and implement, prior
to land disturbance, an effective, approved erosion
and sediment control plan or similar administrative
document that specifies erosion and sediment control
provisions. 3.2B Construction Site Chemical Control.
- Limit application, generation, and migration of toxic substances;
- Ensure the proper storage and disposal of toxic materials;
- Apply nutrients at rates necessary to establish and maintain vegetation without causing nutrient runoff to surface waters; and
- Prepare and implement an effective, approved chemical control plan that contains chemical control provisions.
|
.: top of page |
 Existing Development 3.3A Existing
Development. Develop
and implement watershed management programs to reduce
runoff pollutant concentrations and volumes from existing
development, including:
- Identify priority local and/or regional watershed pollutant reduction opportunities;
- Specify a schedule for implementing appropriate controls;
- Limit destruction of natural conveyance systems; and
- Where appropriate, preserve, enhance, or establish buffers along surface waters and their tributaries.
|
.: top of page |
 Onsite Wastewater Treatment Systems (OWTS)
3.4A New OWTSs. Ensure that new
OWTSs are located, designed, installed, operated, inspected,
and maintained to prevent the discharge of pollutants
to the surface of the ground and, to the extent practicable,
reduce the discharge of pollutants into ground water. 3.4B Operating OWTSs. Establish and
implement policies and systems to ensure that existing
OWTSs are operated and maintained to prevent the discharge
of pollutants to the surface of the ground and, to the
extent practicable, reduce the discharge of pollutants
into ground water. |
.: top of page |
 Transportation Development 3.5A Planning, Siting, and Developing
Roads and Highways. Plan, site, and develop
roads and highways to:
- Protect areas that provide important water quality benefits or are particularly susceptible to erosion or sediment loss;
- Limit land disturbance such as clearing and grading and cut and fill to reduce erosion and sediment loss; and
- Limit disturbance of natural drainage features and vegetation.
3.5B Bridges. Site, design, and
maintain bridge structures so that sensitive and valuable
aquatic ecosystems and areas providing important benefits
are protected from adverse effects. 3.5C Construction Projects. Reduce
erosion and, to the extent practicable, retain sediment
on site during and after construction. Prior to land
disturbance, prepare and implement an approved erosion
control plan that contains erosion and sediment control
provisions. 3.5D Chemical Control.
- Limit application, generation, and migration of toxic substances;
- Ensure the proper storage and disposal of toxic materials;
- Apply nutrients at rates necessary to establish and maintain vegetation without causing significant nutrient runoff to surface waters.
3.5E Operation and Maintenance. Incorporate
pollution prevention procedures into the operation
and maintenance of roads, highways, and bridges to
reduce pollutant loadings to surface waters. 3.5F Road, Highway, and Bridge Runoff Systems. Develop
and implement runoff management systems for existing
roads, highways, and bridges to reduce runoff pollutant
concentrations and volumes entering surface waters.
Identify priority watershed pollutant reduction opportunities,
and establish schedules for implementing appropriate
controls. |
.: top of page |
 Education/Outreach
3.6A Pollution Prevention
Education/Outreach. Implement
educational programs to provide greater understanding
of watersheds and raise awareness, and to increase
the use of applicable urban management measures and
practices where needed. Public education, outreach,
and training programs should involve applicable user
groups and the community. |
.: top of page |
|
|
