R. Pitt
Copyright August 2005
Module 1: Stormwater Regulations
Excerpted
from Chapter 15, Stormwater Quality
Management, R. Pitt, forthcoming book
Early Court Cases Concerned with the Effects of Urban
Runoff
Jurisdiction Over Urban Runoff Problems
Summary of the Total Maximum Daily Load (Tmdl) Program
General Information for the TMDL Program
Selected
Southeastern State Programs
Summary of Stormwater Regulations
Construction Site Runoff Problems
Site Specific Factors Affecting Construction Site Erosion
in Birmingham Area
Factors Affecting Controllability of Construction Site
Runoff
Actual Field Performance of Most Construction Site
Erosion Controls has been Disappointedly Low
Prevention is the Best and Typically Least Expensive
Solution
Local and State Controls of Urban Runoff
Example Construction Site Erosion Control and Stormwater
Management Requirements
Standards and Specifications for Construction Site
Erosion Control
Purpose of Erosion Control Requirements
Site Erosion Control Requirements
Summary of Erosion Control Requirements
Standards and Specifications for Stormwater Runoff
Control
Purpose of Stormwater Control Requirements
General Runoff Volume Criteria
Purpose and Benefits of Specific Runoff Control
Requirements
Discharge Quality Requirements for Stormwater
Selection of Stormwater Controls
Special Considerations for the Control of Stormwater
Toxicants
Need for Adequate Design and Inspection
Requirements for an Example Watershed Protection
Ordinance
Potential Applicability of Example Stormwater Runoff
Quality Requirements for Different Land Uses
Summary of Regulations and Public Education as Stormwater
Control Benefits
Significant elements of a successful stormwater management
program involve regulations and associated public education. Without the
support of the community, especially their financial support, stormwater
management in an area is destined to failure. This module briefly describes
some of the emerging public education activities that have been shown to be
successful. It also describes the history of stormwater regulations in the
For any regulations to work there will need to be an existing framework within which to place the regulations (e.g., local ordinances, zoning, planning regulations, etc.) together with dedicated resources to enforce them. Without the institutional systems to set them up and enforce them, they will not be effective. Regulations can be an important pollution prevention practice, with particular application to new developments. This should ensure that the pollution is prevented or controlled at the source, and any implementation and maintenance costs are included as part of the costs of development. Some typical regulations include:
· Land use regulations
- zoning ordinances
- subdivision regulations
- site plan review procedures
- natural resource protection
· Comprehensive stormwater control regulations
· Land acquisition
Further details on a regulatory approach are contained in Handbook: Urban Runoff Pollution Prevention and Control Planning (Metcalf & Eddy 1993).
Public education can have a significant role to play because an aroused and concerned public has the power to alter behavior at all levels. However if stormwater management plans are not adequately described and if the public opinion is not considered, the public can work against the implementation of a stormwater plan if viewed as an unnecessary extra cost and as a restriction on freedom (Field, et al. 1994). Gaining the public support, as with all education, is a continuous process and applies to all sectors of the public. However, Poertner (1980) identified public education as perhaps the most neglected phase of solving stormwater problems. He found that very few areas had good public information or community relations programs. Those that had them found them to be helpful in making the public aware of the needs of the community and in obtaining their support, especially when approving improvement bond ballot issues.
The residential sector is made up of everyone living in a drainage area. Long-range education goals can be tackled through school programs and short-range goals may be achieved through community groups. Advantage should be taken of working with groups looking for community improvement projects and opportunities arising from news media coverage and the associated publicity.
The commercial sector is a fairly large and often diffuse group. Both the owners/managers and their staff will need to be included in any communication activity. Methods of communication may include news announcements in the local press, mailed news items, individual contact, and follow-up contacts to answer questions and to educate new employees. Public education can benefit from failures, such as violations of regulations which result in a citation or fine, and reported in the local press. This not only informs the public about regulations, but it also provides an incentive for the regulations to be followed.
The industrial sector is a smaller group and can be educated by direct contact, education of the consultants from whom industry seeks advice, and by education of trade associations. Indirect education opportunities are provided by speaking to meetings of professional organizations and by writing in professional newsletters and journals. Industrial decision makers are a relatively small group, which, when informed or made aware of their obligations, are likely to respond.
Stormwater managers should also communicate with other public officials and governmental institutions to ensure that they are aware of the stormwater management program and its implications. Examples include: road, sanitation, and parks departments; and workers at public institutions such as hospitals and prisons.
Schumacher and Grimes (1992) gave a detailed description of
the
1) Define
the issues. The public needs to be aware that federal and possibly state
regulatory issues define much of the stormwater program requirements and
therefore costs. However, many local concerns also define the specific need.
The public education program needs to let the public know how the local
government plans to address the specific issues and concerns, and how much it
will cost. Explaining the function of a public utility, or other funding
mechanism, is also important.
2) Set objectives. The public education program was also needed to inform and educate the stakeholders and the public at large. It was also needed to seek input, and to involve them through the establishment of a citizen task force. Consensus for the stormwater management program was another important goal of the public education program, as well as monitoring the effectiveness of the public education program through follow-up surveys and other vehicles.
3) Identify resources. After the issues and objectives were established, the next step was identifying the available resources. This included public staff and the citizens task force.
4) Outline and conduct activities and tasks. The above three steps enabled this action step to proceed. The development of promotional material, conducting surveys, setting up a hot line, producing newsletters, handling the media, developing slide shows, making presentations at stakeholder meetings and neighborhood meetings, sponsoring special events, and holding public hearings were all important elements of the Charlotte public education program.
Charlotte felt that this program was extremely successful, but recommended several improvements, including having better records of complaints and better cost estimates for the public (specifically, not glossing over details, or dumbing-down information, but making the information clearer in presentations), to use the hot line to measure the program’s success, and to form the citizen’s task force earlier in the process.
A multi-level, multi-target public education program can help to avoid problems in implementing a stormwater management program. Further information on describing the stormwater management program to the public can be found in Designing an Effective Communication Program: A Blueprint for Success (Beech and Dake 1992), and Urban Runoff Management Information/Education Products (EPA 1993).
An example of a successful public education effort for
stormwater control has been occurring in
Programs to enhance public education and public
participation in reducing surface water pollution were required components of
the NPDES stormwater management plans submitted by large and medium sized
cities to the EPA. The Sewerage and Water Board of New Orleans, the New Orleans
Public School System, the Lake Pontchartrain Basin Foundation, and the EPA
sponsored a local award winning public education program in
Hennepin Parks, of the Twin Cities area of
A new resource has recently been announced for environmental
education. The National Environmental Education Standards Project at
An important question concerning public education has been
measuring its direct water quality benefits. There has been little debate
concerning the intrinsic value of public education in stormwater management.
However, there has been no quantified measure of receiving water improvements
after its implementation. The Texas Natural Resources Conservation Commission
and Texas Watch are conducting an EPA sponsored evaluation of public education
programs in Austin (EPA 1996). A paired watershed monitoring program is being
conducted in East Bouldin Creek, one of the most polluted urban creeks in
Water use laws in the
Most of the states east of the
The Western states have mostly adopted prior appropriation water use laws. Appropriation is made by diverting the water from the water course and applying it to a beneficial use. Early acquired water rights have the highest priority and can take their full share in times of shortages. If the water right is not used, it can be lost. Historically, beneficial uses were measured by their economic value and water quality and wildlife uses had low values. Some states require minimum flows to protect these “uneconomical” uses.
Point sources of water pollution are defined in Section 502 of the 1972 Amendments to the Water Pollution Control Act as “any discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged.” Non-point sources are the remaining pollutant sources, not included in this definition of point sources. This point source definition appears to include almost all water discharges, but important court actions have been necessary to clarify it still further. The most important non-point sources are usually considered to be agricultural, mining, forestry and urban runoff.
Before 1948, almost all water pollution control authority was vested in the states and local governments. The legal powers of the different state agencies varied greatly. Funding of Publicly Owned Treatment Works (POTW) was especially difficult. The Public Health Service Act of 1912 authorized the investigation of pollution in navigable waters, and the Oil Pollution Act of 1924 was to prevent oil discharges into navigable waters. The Water Pollution Control Act (WPCA), PL 80-845, was passed in 1948 to establish some federal authority in abating interstate water pollution. The 1948 act suffered from the use of receiving water standards instead of effluent standards and ineffective enforcement (Hanks, Tarlock and Hanks 1974). The receiving water standards only considered the current uses of the water and were difficult to enforce against any single discharger. It was usually not possible to determine which discharger was responsible when the stream standard was exceeded. The early regulations also placed much of the burden of proof on the enforcement agencies. Most of the following water pollution control legislation has been amendments to this 1948 act. Important amendments were passed in:
· 1956 (making the legislation permanent and to fund construction grants for POTWs),
· 1961 (increased funding for water quality research and construction grants),
· 1965 (increased construction grants and started research concerning combined sewer overflows),
· 1966 (removed the dollar limit on construction grants),
· 1972 (the most important advances to this date),
· 1977 (to extend some of the deadlines established in the 1972 amendments), and
· 1988 (to require discharge permits for stormwater).
The Refuse Act of 1899 (33 USC 407) was used in 1970 to establish a discharge permit system. This act prohibited the discharge of any material, except sewage and runoff, into navigable waterways without a permit from the Dept. of the Army. This law was written during the "Progressive Conservation Era", when multiple uses of natural resources were first seriously considered. The US Supreme Court upheld the applicability of the law for pollution control in 1966. A court decision later invalidated the program in 1971, however. Because of these difficulties, the WPCA Amendments of 1972 (PL 92-500) contained a permit program, called the National Pollutant Discharge Elimination System (NPDES). The NPDES is the enforcement scheme to control effluent from point sources. The permits are required for all point sources and establish discharge limits based on the available control technology. The discharge limits were set for each industry, based on a series of studies that characterized each industry's waste effluents and existing controls. Future discharge limits were reduced as all facilities were to obtain “best available technology economically achievable” (BATEA) by July 1983. New sources were to obtain discharges representative of a “standard of performance” that was much more restrictive. Non-point sources were originally exempt from the NPDES permit program, but stormwater discharges will be included in the NPDES system under the 1988 EPA proposals (FR CFR 122, 123, 124, and 504, as published in the Federal Register of December 7, 1988).
The NPDES was to enable Congress’ goal of no pollutant discharges whatsoever by 1985. Other goals of PL 92-500 included the protection and propagation of fish, shellfish, and wildlife and recreational uses of water by July 1983, to prohibit the discharge of toxic pollutants, to continue the funding of POTWs, to develop areawide wastewater treatment management plans, to fund a major resource and demonstration effort to improve treatment technology, and to protect the rights of the States to reduce pollution and to plan their water resources uses.
The 1977 Amendments (PL 95-217) extended some of the deadlines, but no waivers were allowed for toxic pollutant discharges. Ad valorem taxes by municipalities to fund treatment projects were allowed, incentives were made for innovative technology, and increased emphasis was placed on the areawide treatment planning (Section 208) studies.
The “208” planning studies, which have been completed, recognized the need to control non-point pollution in order to meet the Congressional goals. This section was an incentive to local governments to develop their own plans, with minimal federal input. These plans were to characterize all point and non-point pollutant discharges in designated areas and to develop treatment schemes that would allow the goals to be met. The results of these plans effect the issuance of NPDES permits. Unfortunately, most of these plans were conducted in short time periods with limited technical success. Control measures were recommended with few local demonstrations of their potential success (especially for non-point pollution control). Recognizing these technical short-comings, Congress authorized the Nationwide Urban Runoff Program (NURP) to demonstrate the applicability of various urban runoff control measures in about 30 cities. These studies were completed in 1983 (EPA 1983). With these results, the 208 plans are to be revised under Section 205g. It is foolish to require expensive and possibly low cost-effective controls for point sources when non-point sources are contributing much of the waste loads to a receiving water. Much of these “non-point” discharges are originating from industrial areas (Pitt and McLean 1986) and are mostly caused by “poor housekeeping” (truck spills, dirty storage areas, inadequate refuse collection, etc.), by fugitive air pollutants which settle out over the area, and, possibly most importantly, by direct connections of certain waste streams to the storm drainage system (wash waters, etc.).
There have been various other laws affecting non-point water quality management. The most important ones include the National Environmental Policy Act of 1969 (PL 91-190) which requires environmental impact studies, and the Toxic Substances Control Act of 1965 (PL 94-469).
Several court cases have considered the question of whether urban runoff is a point source (and therefore required to have a NPDES permit under the original program) or a non-point source (and exempt from the permit process, but still subject to applicable discharge standards). Urban runoff enters receiving waters usually through a conduit, or sometimes through a ditch (open channel). The Natural Resources Defense Council (NRDC) v. Costle et al. (568 F.2D 1369, 1977) case found that uniform NPDES discharge limitations were not a necessary precondition for inclusion of agricultural, silvicultural and stormwater runoff point sources into the NPDES program. The regulations (40 CFR Section 125.4, 1975) did, however, specifically exempt separate storm sewers containing only storm runoff uncontaminated by any industrial or commercial activity. This case pointed out that the NPDES program clearly establishes that the discharge of any pollutants is unlawfull: no one has the right to pollute. The pollution continues because of technological limits, not because of any inherent rights to use the nation's waterways for the purpose of disposing of wastes. The exclusion noted above was for administrative reasons, as it was felt that requiring permits on the approximately 100,000 urban runoff point sources would reduce the ability of the EPA to administer the more important industrial and municipal point sources. A plan to use general permits to cover these discharges may be implemented by the states. The District of Columbia Court of Appeals concluded that the Congressional intent was to require permits for all point sources, but that the EPA was also to have flexibility in structuring the permits in the form of general or area permits. The Court concluded that the remedy lies with Congress if the EPA is not responsive.
Pedersen et al.,
v. Washington State Dept. of Trans. (611 P.2D 1293, 1980) stated that:
"Separate storm sewers, as defined in this section, are point sources
subject to the NPDES permit program. Separate storm sewers may be covered
either under individual NPDES permits or under the general permit". The
State of
United States of American v. Frezzo (642 F.2D 59, 1981) stated that the intent of the NPDES regulations “is to exclude from the NPDES permit program all natural runoff from agricultural land which results from precipitation events.” This case further stated: “When water pollution from irrigation ditches results from precipitation events, that pollution is non-point in nature. However, when discharges from irrigation ditches result from the controlled application of water by any person, that pollution is considered point source and subject to the program proposed herein.” Therefore, urban runoff appears to be considered as a point source, while agricultural ditches are non-point sources during rains and point sources during irrigation periods. Again, the 1988 EPA regulations require discharge permits for certain classes of urban runoff discharges.
There have been many court cases that have tried to identify
the parties responsible for causing problems involving urban runoff. The
earliest concerns of urban runoff generally involved flooding or decreased
flows. When agricultural or undeveloped land is urbanized, much of the land
surface is paved with impervious materials (asphalt and concrete). This
increases the runoff volumes and rates during rains, and decreases the
receiving water flows during dry periods. Several cases have been tried around
the country concerning flooding or decreased flows due to urban development.
The Orange County Water District sued the City of
Water quality questions concerning non-point sources have
also been addressed in the courts. The effects of salts in roadway runoff was
examined in
Urban runoff may also affect groundwater. Early studies have
detected increased salt concentrations in shallow groundwaters in locations
where large quantities of salts are used on roads for ice control. The Sierra
Club sued Edwards Underground Water District et al., in 1974 (502 F. 2D 43) hoping to protect a local aquifer
from the unknown effects of urban runoff. The Environmental Defense Fund et
al., sued Costle et al., in 1977 (439
F. Supp. 980) concerning the decreasing recharge of the
The Central Contra Costa Sanitary District in
Cox (1983) summarized recent water law analyses and found that much attention has been given to questions of federalism relating to implementing of water pollution regulations. Dexter and Schwarzenbart (1982) examined the development of federal common laws of nuisance, relating to water pollution discharges. They felt that Congress did not intend to preempt these common laws with the Clean Water Act. Vance (1982) expressed the need for the federal common law as a mechanism for determining liability of polluters for resulting injury. The elimination of the common law was thought to insulate polluters from liability, especially if pollution across state boundaries was of concern.
The EPA regulations to
control stormwater runoff were first published in the Dec. 7, 1988 issue of the
Federal Register. These regulations initiated a permit process for urban
runoff, but the reporting information required and the schedules vary depending
on the land use and the size of the community. The EPA was required by Section
405 of the Water Quality Act of 1987 to establish permit application
requirements for large municipalities (having populations greater than 250,000)
and industrial concerns (including construction operations) by February 4,
1989. Permit application requirements for municipalities having populations
between 100,000 and 250,000 were to be established by February 4, 1991. The
first applications (for the industries and large cities) were to be submitted
by February 4, 1990. The applications for the smaller cities were to be filed
by February 4, 1992. Permits are now required for smaller cities also, as part
of the second phase of the NPDES stormwater permit program.
The phase one general
application requirements stressed descriptive information concerning the
drainage area, with minimal runoff monitoring requirements. The permit
applications mostly relied on the use of simple models to predict annual
discharges of pollutants and field analyses for detecting illicit connections
and illegal dumping. The permit applications also required a description of any
locally required stormwater and construction site runoff controls. Local
municipalities were also to establish authority for managing stormwater.
The Clean Water Act 402(p)(6) initial phase II rule (for small municipalities) was published on August 7, 1995. Its purpose was to designate additional sources of stormwater that needed to be regulated to protect water quality. It required all unregulated sources of storm water discharges to apply for NPDES permits by August, 2001. It affects millions of industrial/commercial facilities, and almost all construction activities. A Federal Advisory Committee (FACA) helped develop the Phase II rule. The committee’s membership included a cross-section of interested stakeholders and they held 14 meetings from 1995 – 1998. They circulated three preliminary drafts for review and comment
When it was finalized, the Stormwater Phase II Rule superseded the August 1995 regulation. The original draft was published in Jan. 9, 1998 Federal Register 40 CFR Parts 122 and 123, 63 FR 1563. During the 90-day comment period, more than 550 comments were received. The EPA held public hearings at 6 locations to explain the phase II proposal and to obtain public comment. The final rule was published on December 8, 1999 in the Federal Register.
Two new classes of facilities were designated for automatic coverage on a nationwide basis:
1) small municipal separate storm sewer systems located in urbanized areas (about 3,500 municipalities) [phase I included medium and large municipalities]
2) construction activities that disturb less than 5 acres of land (about 110,000 sites a year) [phase I included construction sites larger than 5 acres]
A “no exposure” incentive for phase I sites was also proposed for industrial activities. This would exclude about 70,000 facilities. The NPDES permitting authority would need to issue permits (most likely general permits) by May 31, 2002. The rule would require that regulated small MS4 permit programs contain the following components:
· develop, implement, and enforce a program to reduce discharge of pollutants and protect water quality to the “maximum extent practicable”
· must include six minimum control measures:
- public education and outreach
- public involvement and participation
- illicit discharge detection and elimination
- construction site storm water runoff control
- post-construction storm water management in new development and redevelopment
- pollution prevention and good housekeeping for municipal operations
· must submit a notice of intent (NOI) or permit application and identify for each minimum control measure:
- best management practices
- measurable goals
- timeframe for implementation
- responsible persons
· must evaluate program and submit reports
Flexibility was intended for the phase II rule by encouraging the use of general permits, by encouraging municipalities to determine appropriate stormwater controls, by not require extensive monitoring by permittees, and by recognizing the use of existing programs, including existing structures and mechanisms for public participation.
The construction site regulations extends existing phase I regulation for construction coverage to all sites that result in the disturbance of 1 acre or more, but less than 5 acres (designated nationwide) and for all sites that result in disturbance of less than 1 acre (potential designation by permitting authority). The rule requires the use of an ordinance that controls erosion and sediment to the maximum extent practicable, controls other waste at construction sites, sets waivers by the permitting authority, and qualifies local and state programs. The phase II rule waives coverage for construction sites that have a rainfall erosivity factor (NRCS RUSLE rainfall factor “R”) of less than 2 (during the period of construction) (“low rainfall”), an annual soil loss of less than 2 tons/acre/year (“low erosion potential”), or a watershed plan, or TMDL assessment, that addresses the pollutants of concern
1) ensures control of other waste at construction sites (discarded building materials, concrete truck washout, sanitary waste, etc.)
2) implements appropriate best management practices (such as silt fences, temporary detention ponds, etc.)
3) requires pre-construction reviews of site management plans
4) receives and consider public information
5) requires regular inspections during construction
6) has penalties to ensure compliance
If local regulations incorporate the following principles and elements into its stormwater program, then it would be considered as a “qualifying” program that meets Federal requirements.
· Five Principles
1) good site planning
2) minimize soil movement
3) capture sediment
4) good housekeeping practices
5) mitigation of post-construction stormwater discharges
· Eight Elements
1) program description
2) coordination mechanism
3) requirements for nonstructural and structural BMPs
4) priorities for site inspections
5) education and training
6) exemption of some activities due to limited impacts
7) incentives, awards, and streamlining mechanisms
8) description of staff and resources
The timeframes for implementation of the new municipal and construction permits are 2 to 3 years for permit issuance and NOIs within 90 days of permit issuance.
Another important emerging regulation affecting drainage and stormwater quality is the TMDL program. The following is summarized from the report of the Federal Advisory Committee on the TMDL Program, published on July 1998.
The TMDL program is aimed specifically at assuring attainment of water quality standards by requiring the establishment of pollutant loading targets and allocations for waters identified as not now in attainment with those standards. Section 303(d)(1) of the Clean Water Act provides that states, with EPA review and approval, must identify waters not meeting standards, and must establish total maximum daily loads (TMDLs) for them to restore water quality. If the states do not complete these actions, EPA must do so.
The Clean Water Act has produced significant and widespread improvements in water quality over the last quarter‑century. Knowledge and understanding of water quality problems and the tools to address those problems have advanced in that time as well, but many waters still do not meet State water quality standards, and TMDLs have not been established for most of those waters.
The final National Water Quality Inventory Report to
Congress for 1996 indicated that of the 19% of the nation’s rivers and streams
that have been evaluated, 35% do not fully support water quality standards, or
uses, and 8% are considered threatened. Of the 72% of estuary waters evaluated,
38% are not fully supporting uses/standards and 4% are threatened. Of the 40%
of lakes, ponds and reservoirs evaluated (not including the
Under section 303(d)(1), states are required to identify and establish a priority ranking for waters not meeting water quality standards, taking into account the severity of the pollution and the uses to be made of the waters. The EPA is required to review each state’s list of impaired waters. Once the list is established, the states are to develop a TMDL for each listed water. The EPA is also required to review each TMDL (within 30 days of submittal by the State). If the EPA does not approve the list of impaired waters or the state’s TMDL plan, it is required to establish acceptable lists and plans. A water may be in nonattainment for some parameters, but not for others. Generally, the TMDL program uses a parameter specific approach. However, the use of a broad, watershed approach, considering all water quality problems and their related causes and solution, is to be preferred and encouraged.
In general, a TMDL is a quantitative assessment of water quality problems, contributing sources, and pollution reductions needed to attain water quality standards. The TMDL specifies the amount of pollution or other stressor that needs to be reduced to meet water quality standards, allocates pollution control, or management responsibilities among sources in a watershed, and provides a scientific and policy basis for taking actions needed to restore a waterbody.
In 1991, the EPA published guidance explaining the role of TMDLs in watershed protection. In 1992, the EPA amended its regulations to describe in greater detail requirements for states to submit lists of waters needing TMDLs. Among other things, the revised regulations required states to submit lists every two years and to target waters for which TMDLs would be developed during the next two years. Over the past few years, the EPA has continued to publish several additional guidance and policy documents relating to section 303(d)(1) lists and TMDL development.
Beginning in 1986, and escalating since 1996, environmental public interest organizations have filed numerous lawsuits under the Clean Water Act’s citizen suit provision (section 505) alleging that the EPA had failed to carry out its mandatory duty to disapprove inadequate state section 303(d)(1) lists and/or TMDLs, or to carry out state program responsibilities where states have failed to do so.
By mid 1998, all states had EPA‑approved 1996 section 303(d)(1) lists, but the content and scope of these lists varied greatly. Development of TMDLs has been initiated at an increasing pace in some states, but most TMDLs remain to be completed. Many of the waters still needing TMDLs are impaired by contributions from both point and nonpoint sources. The EPA has undertaken a variety of steps to strengthen the TMDL program.
The following are Internet links to various descriptions of the national TMDL program, and to selected southeastern state programs (including 303d listed streams):
http://www.epa.gov/owow/tmdl/index.html
EPA Region 4 Stormwater Permit Information
http://www.epa.gov/region4/water/permits/stormwater.html
General EPA TMDL Information and National 303(d) Listings
http://www.epa.gov/owow/tmdl/states.html
Model Sediment TMDL Assessment Protocol (Limno-Tech)
http://www.nahb.org/fileUpload_details.aspx?contentID=33072
Sediment TMDL Protocol (EPA)
http://www.stormwaterauthority.org/assets/sediment.pdf
Pathogen TMDL Protocol (EPA)
http://www.stormwaterauthority.org/assets/pathogen_all.pdf
General Alabama TMDL program description and links:
http://www.adem.state.al.us/WaterDivision/WQuality/TMDL/WQTMDLInfo.htm
EPA fact sheet for AL 303(d) listed streams:
http://oaspub.epa.gov/waters/state_rept.control?p_state=AL
Storm Water Management Authority,
Mississippi TMDL reports and 303(d) listed streams:
http://www.deq.state.ms.us/MDEQ.nsf/pdf/TWB_2002_303dList/$File/MS2002303dListEV.pdf?OpenElement
MS TMDL program
http://www.deq.state.ms.us/MDEQ.nsf/page/TWB_Total_Maximum_Daily_Load_Section?OpenDocument
Georgia TMDL program and reports (scroll down to Water Quality – Watershed Information, and below)
http://www.dnr.state.ga.us/dnr/environ/gaenviron_files/gaenviro.htm
EPA fact sheet for TN 303(d) listed streams:
http://oaspub.epa.gov/waters/state_rept.control?p_state=TN
TN Stormwater Permit program
http://www.state.tn.us/environment/permits/conststrm.php
EPA fact sheet for FL 303(d) listed streams:
http://oaspub.epa.gov/waters/state_rept.control?p_state=FL
Status of FL TMDL program
http://www.stormwaterauthority.org/assets/153TShelley.PDF
FL Stormwater Permit program
http://www.dep.state.fl.us/water/stormwater/npdes/MS4_1.htm
Water use regulations have been in place in many nations for hundreds of years. These regulations are generally concerned with protection against flooding, and/or sharing water during periods of scarcity. Water quality regulations were first instigated to permit or protect basic beneficial uses of receiving waters, initially restricted to navigation and waste assimilation. In recent decades, protection has been extended to include a broader range of environmental and recreational-based uses.
Early regulations affecting stormwater were based on drainage goals, although some progressive communities did include stormwater quality objectives in local regulations affecting stormwater discharges. The Clean Water Act NPDES program was modified in the late 1980s to specifically include non-point sources of water pollutants. The phase I and phase II stormwater discharge permit programs have now affected most communities in the nation. Another important emerging issue affecting stormwater (and traditional discharges) is the TMDL program affecting all listed impaired waters. These impaired waters must now have a watershed-based allocation and treatment plan to ensure compliance with water quality standards.
· Water quality impairment results from sediment discharged, plus associated pollutants (>70% of P and N in the nations streams from eroded sediment)
· Siltation is second largest cause of impaired water quality in the nations rivers and lakes
· Large amounts of sediment reduce stream flow capacity and destroy important aquatic life habitat
· Effects from construction erosion runoff extends well downstream of construction sites
· Erosion rates from construction sites can be 10X erosion rates from row crops and 100X erosion rates from forests or pastures
· Typical construction site erosion yields are 10 to 150 tons/acre/year
·
Rainfall Energy (
· Soil Erodibility (northern part of state has fine grained, highly erosive soils)
· Site Topography (northeastern part of state has steep hills under development)
· Surface Cover (usually totally removed during initial site grading)
· Rain energy directly related to rainfall intensity
·
Rainfall erosion index varies from 250 to 550+ for
· Months having greatest erosion potential are February and March, while September through November have the lowest erosion potential
· Runoff characteristics (flow volume and rate): high because of about 50 to 65 in/yr rainfall and intense storms
·
Sediment quantity and particle size (from 70 construction site runoff samples
from
- Measured suspended
solids concentrations at
100 to more than 25,000 mg/L (overall median about 4,000 mg/L).
- Turbidity ranged from about 300 to >50,000 NTU, with an average of about 4,000 NTU
- Particle sizes: 90% were smaller than about 20 mm (0.02 mm) in diameter and median size was
about 5 mm (0.005 mm).
|
|
Low intensity rains
(<0.25 in/hr) |
Moderate intensity
rains (about 0.25 in/hr) |
High intensity
rains (>1 in/hr) |
|
Suspended solids,
mg/L |
400 |
2,000 |
25,000 |
|
Particle size
(median), mm |
3.5 |
5 |
8.5 |
Difficult to effectively use design standards from elsewhere due to high flow energies, high SS concentration concentrations, and very small particle sizes.
· Excellent filter fence installations (well maintained and well constructed) provide about 50% control, maximum. Typical monitored performance has shown negligible benefits due to installation and maintenance problems.
· Rock berms in channels are more robust, but still less than about 25% suspended solids control.
· Sediment ponds can be designed to provide good control (>50%) of suspended solids, but they would have to be very large (about 2% of drainage area) to provide significant removal of fine sediment. Effluent turbidity is still typically high.
1) divert flows around exposed soils
2) schedule site activities to minimize amount of exposed soil
3) use temporary mulch
4) use erosion control blankets in sensitive areas (concentrated flow channels, steep slopes)
Many states and cities throughout the
Many state and local agencies throughout the country are
currently using construction site erosion and stormwater control ordinances for
newly developing areas, as shown on Tables Erosion-1 through Stormwater-12.
These tables are derived from a report prepared by the Watershed Management Institute
(1997) for the EPA. The Institute compiled a wealth of information derived from
an extensive survey they sent to numerous state and local stormwater management
agencies throughout the
Table Erosion 1.
Erosion and Sediment Control Exemptions and Waivers
|
Jurisdiction |
|
|
|
<2,500
s.f. |
|
|
Agriculture;
state facilities, projects disturbing < 1,000 s.f. |
|
|
None |
|
|
Single
family homes |
|
|
Agriculture;
forestry; public & private projects in right-of-way that add no
impervious surface, grading projects that don't require grading permit |
|
|
Single
family homes not part of subdivision |
|
|
Agriculture,
forestry, WA DOT projects that comply with Puget Sound Highway Runoff
Program, projects discharged directly to receiving water or piped storm drain
(under certain conditions), < 750 s.f. new impervious surface or <
2,000 s.f. total impervious surface |
|
|
Agriculture,
forestry, projects that disturb < 500 s.f. or total cost < $2,500. |
|
|
None |
|
|
Agriculture,
activities disturbing < 5,000 s.f. |
|
|
Agriculture,
forestry, projects disturbing < 2,000 s.f. |
|
|
Agriculture;
single family homes exempt from detailed ES control plan |
|
|
Agriculture
(Kitsap SWCD stormwater related activities funded by |
|
|
N/A
because state NPDES program exempts projects disturbing < 5 acres |
|
|
Agriculture,
projects disturbing < 5,000 s.f. |
|
|
Agriculture |
|
|
Agriculture |
|
|
|
|
|
None |
|
Urban Drainage and Flood
Control District ( |
State
NPDES permit exempts activities disturbing < 5 acres; other requirements
depend on regulations of 10 local government programs |
|
|
Agriculture,
forestry, activities disturbing < 5,000 s.f., activities disturbing <
500 s.f. if next to water |
|
South Florida Water
Management District |
Agriculture
using closed water management systems |
|
Southwest Florida Water
Management District |
Agriculture
(with site specific Conservation Plan with appropriate BMPs); forestry
(complying with "Florida Silviculture BMP Manual"); single family
homes not in subdivision |
|
Suwannee River Water
Management District |
Agriculture
(with site specific Conservation Plan with appropriate BMPs); forestry
(complying with "Florida Silviculture BMP Manual"); single family
homes not in subdivision |
|
State of |
Agriculture |
|
Florida Department of
Environmental Protection |
Agriculture
(if using approved Conservation Plan with appropriate BMPs); forestry
(complying with "Florida Silviculture BMP Manual"); single family
homes not in subdivision |
|
Maryland Department of
the Environment |
Agriculture;
activities disturbing < 5,000 s.f. or 100 cu. yds. |
|
State of |
Agriculture,
forestry, single family homes not part of larger development, activities
disturbing < 5,000 s.f. |
|
State of |
Construction
sties < 5 acres and not located; within ˝ mile of a water classified as a
High Quality Water, in a coastal county and draining to a saltwater or other
classified water, and located in a non-coastal county and draining to or
within one mile of a water classified as a High Quality Water or an
Outstanding Resource Water. |
|
State of |
Timber
harvesting disturbing < 25 acres; agricultural plowing & tilling
pursuant to conservation plan; activities disturbing < 5 acres |
|
State of |
Agriculture,
forestry, single family homes not part of large development, utility
operations with certificate of environmental compatibility |
|
State of |
Agriculture;
forestry; activities disturbing < 10,000 s.f.; mining & gas
exploration activities |
|
Washington State
Department of Ecology |
Agriculture,
forestry operation (except for forest conversions); activities disturbing
< 1 acre; single family homes |
Table Erosion 2.
Erosion and Sediment Control Preferred Practices
|
Jurisdiction |
|
|
|
Sediment
basins & traps designed to capture 15 cu. yds/acre drainage area. |
|
|
Sediment
basins & traps designed to capture 1,800 cu. yds/acre drainage area. |
|
|
Sediment
basins & traps to contain runoff volume from: 10 yr storm for sites <
5 ac., or > 0.25 mi from waters; 20 yr storm for sites > 5 ac. or <
0.25 mi from waters |
|
|
Sediment
basins & traps designed for 100 cu. yds/acre |
|
|
Sediment
basins & traps to hold 2-yr (24 hr) storm volume. |
|
|
Sediment
basins & traps to capture 2.33 yr (6 hr) storm. |
|
|
Sediment
traps to retain runoff volume from 2 yr (24 hr) storm. Basins sized to settle
medium silt soil particles (0.02 mm) during peak discharge from 10 yr (24 hr)
storm. |
|
|
Sediment
basins & traps to capture 1,800 cu. ft./acre drainage area. |
|
|
Sediment
basins & traps to capture 67 cu. yds./acre drainage area. |
|
|
Sediment
basins & traps to contain 1,800 cu. yds runoff from drainage area. |
|
|
Sediment
traps to hold 2 yr (24 hr) storm runoff; basins to treat 10 yr (24 hr) storm. |
|
|
Sediment
traps to treat 2 yr (24 hr) storm runoff; basins sized for 10 yr (24 hr)
storm. |
|
|
Sediment
traps & basins to treat runoff from 2 yr (24 hr) storm. |
|
|
None |
|
|
Sediment
basins & traps to capture 1,800 cu. ft/acre drainage area (to be changed
to 3,600 cu. ft./ac.) |
|
|
Sediment
basins & traps to capture 1,800 cu. ft/acre drainage area (to be changed
to 3,600 cu. ft./ac.) |
|
|
Sediment
basins & traps to capture runoff from 10 yr (24 hr) storm |
|
|
|
|
|
Sediment
basins & traps to capture runoff from 10 yr (24 hr) storm (RARELY USED) |
|
Urban Drainage and Flood
Control District ( |
Sediment
basins & traps to retain 0.25 in of runoff from site. |
|
|
Sediment
basins & traps to capture runoff from 10 yr storm |
|
South Florida Water
Management District |
None |
|
Southwest Florida Water
Management District |
Sediment
basins & traps to capture 67 cu. yds./acre drainage area |
|
Suwannee River Water
Management District |
Sediment
basins & traps to capture 67 cu. yds./acre |
|
State of |
Sediment
traps & basins to retain 3,600 cu. ft./acre of contributing drainage
area. |
|
Florida Department of
Environmental Protection |
Sediment
basins & traps to capture 67 cu. yds./acre |
|
Maryland Department of
the Environment |
Sediment
basins & traps to treat 1 in of runoff from disturbed area |
|
State of |
Sediment
basins & traps to retain 1 inch of runoff from disturbed area |
|
State of |
Preventive
Measures (nonstructural controls) |
|
State of |
Sediment
basins to treat 7,000 cfs/acre; sediment traps to treat 2,000 cfs/acre (max.
5 acres) |
|
State of |
Sediment
basins & traps to achieve 80% removal of average annual total suspended
solids loading |
|
State of |
Sediment
basins to capture 134 cu. yds/acre |
|
Washington State
Department of Ecology |
Sediment
basins & traps to detain 10 yr (24 hr) developed condition design storm |
Table Erosion 3.
Erosion and Sediment Control Allowed Practices
|
Jurisdiction |
|
|
|
Silt
fences, gravel const. entrance, slope protection, temp. & perm. veg.
stabilization |
|
|
Construction
sequencing, rock berms, filter dikes, diversion swales, temporary &
permanent vegetation stabilization |
|
|
Seasonal
limits on disturbed area, silt fence, gravel construction entrance, wheel
washes; slope protection; temporary & permanent vegetation stabilization |
|
|
Straw
bales, surface roughening, diversions, gravel filters, filter fence, inlet
barriers, terraces, temporary & permanent vegetation stabilization |
|
|
Seasonal
limits on disturbed area, silt fence, straw bales, gravel construction
entrance, slope protection, inlet prot., temp. & permanent vegetation
stabilization |
|
|
Silt
fences, gravel construction entrance, inlet protection, temporary &
permanent vegetation stabilization, limited exposed areas |
|
|
Silt
fences, gravel construction entrance, wheel wash, slope protection, inlet
protection, temporary & permanent vegetation stabilization |
|
|
Silt
fences, vehicle wash area, straw bales, stabilized construction entrance,
inlet protection, temporary & permanent vegetation stabilization |
|
|
Silt
fences, straw bales, inlet & slope protection, temp. & perm. veg.
stabilization. |
|
|
Silt
fences, straw bales, inlet & slope protection, temp. & perm. veg.
stabilization. |
|
|
Seasonal
limits on disturbed area, stabilized construction entrance, wheel wash, slope
drain, straw bales, silt fence, mulching, temp. & perm. vegetation
stabilization. |
|
|
Seasonal
limits on disturbed area, mulching, silt fences, gravel construction
entrance, slope drains, temporary & permanent vegetation cover. |
|
|
Seasonal
limits on land disturbance, gravel construction entrance, wheel wash, silt
fences, straw bales, slope drains, mulching, temp. & perm. vegetative
stabilization |
|
|
None |
|
|
Mulching,
sodding, staged clearing, silt fences, gravel construction entrances,
temporary & permanent vegetation |
|
|
Mulching,
sodding, staged clearing, silt fences, gravel construction entrances,
temporary & permanent vegetation |
|
|
Mulching,
seasonal limitation on disturbed area, silt fences, gravel construction
entrance, slope drains, temporary & permanent vegetative stabilization |
|
|
|
|
|
Silt
fences, gravel construction entrances, diversions, bio-bags, straw, compost,
temporary & permanent vegetation cover |
|
Urban Drainage and Flood
Control District ( |
Mulching,
silt fences, temporary & permanent vegetation cover |
|
|
Temporary
& permanent vegetative cover; mulching; seeding; sodding; erosion
blankets; silt fences; gravel construction entrances; outlet stabilization |
|
South Florida Water
Management District |
None
listed. |
|
Southwest Florida Water
Management District |
Mulching;
sodding, staged clearing, silt fences, gravel construction entrance,
temporary & permanent vegetative cover |
|
Suwannee River Water
Management District |
Mulching,
sodding, staged clearing, silt fences, gravel construction entrances,
temporary & permanent vegetation |
|
State of |
Silt
fences, straw bales, gravel construction entrances, diversions, slope drains,
temporary & permanent vegetation stabilization |
|
Florida Department of
Environmental Protection |
Mulching,
sodding, staged clearing, silt fences, gravel construction entrances,
temporary & permanent vegetation |
|
Maryland Department of
the Environment |
Mulching,
sodding, staged clearing, silt fences, gravel construction entrances,
temporary & permanent vegetation |
|
State of |
Mulching,
sodding, staged clearing, silt fences, gravel construction entrances,
temporary & permanent vegetation |
|
State of |
Preventative
measures, detention and retention ponds and infiltration devices such as
infiltration basins, trenches or underground trenches and dry wells |
|
State of |
Silt
fences, temp. & perm. vegetation, diversions, rock filters, riprap, inlet
protection |
|
State of |
Mulching,
sodding, staged clearing, silt fences, gravel construction entrances,
temporary & permanent vegetation |
|
State of |
Sediment
traps, silt fences, temp. & perm. veg., diversions, daily street cleaning |
|
Washington State
Department of Ecology |
Seasonal
disturbed area limits, staged clearing, silt fences, gravel construction
entrance, mulching, sodding, temporary & permanent vegetative cover,
slope drains |
Table Erosion 4. Erosion
and Sediment Control Design Criteria Publications
|
Jurisdiction |
|
|
|
|
|
|
City's Environmental Criteria Manual |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
City of |
|
|
|
|
|
|
|
|
|
|
|
Stormwater Management Manual for the |
|
|
Stormwater Management Manual for the |
|
|
Stormwater Management Manual for the |
|
|
None |
|
|
|
|
|
|
|
|
Snohomish County Stormwater Management Manual (based on criteria
in |
|
|
|
|
|
Erosion Control Plans Technical Guidance Handbook |
|
Urban Drainage and Flood
Control District ( |
Urban Storm Drainage Criteria Manual, Volume 3 - BMPs |
|
|
Best Management Practices for |
|
South Florida Water
Management District |
|
|
Southwest Florida Water
Management District |
|
|
Suwannee River Water
Management District |
|
|
State of |
|
|
Florida Department of
Environmental Protection |
|
|
Maryland Department of
the Environment |
|
|
State of |
Standards for Soil Erosion and Sediment Control in |
|
State of |
State of |
|
State of |
Discharge rate for temporary basins = 1.6 cfs/acre (2 yr storm);
for permanent basins, discharge rate = 2.75 cfs/acre (25 yr storm); |
|
State of |
A Guide to Site Development and Best Management Practices for
Stormwater Management and Sediment Control; |
|
State of |
|
|
Washington State
Department of Ecology |
Stormwater Management Manual for |
Table Stormwater 1.
Stormwater Management Program Exemptions and Waivers
|
Jurisdiction |
Exemptions
and Waivers |
|
|
<2,500 s.f. |
|
|
Agriculture, state
facilities, single family homes platted lots, & subdivisions (min. lot
size > 5 acres) |
|
|
Agriculture, forestry,
single family homes not part of plat |
|
|
Agriculture, forestry not
covered in ordinance |
|
|
Agriculture, forestry,
single family homes, other minor projects |
|
|
Single family homes not
part of subdivision |
|
|
Agriculture, forestry
(except when converting to other uses), WA DOT projects that comply with
Puget Sound Highway Runoff Program, projects discharged directly to receiving
water or piped storm drain (under certain conditions), < 750 s.f. new
impervious surface or < 2,000 s.f. total impervious surface |
|
|
Agriculture, forestry,
single family homes (lot size > 2 acre), projects disturbing < 5,000
s.f. |
|
|
Single family homes not
part of subdivision |
|
|
Agriculture, forestry,
residential < 2 acre lot size AND disturb < 5,000 s.f. |
|
|
Agriculture, forestry,
projects < 2,000 s.f. impervious, industrial/commercial projects <
1,000 s.f. new impervious surface |
|
|
Projects < 5,000 s.f.
impervious surface; projects w/ discharge < 0.5 cfs; single family homes
not part of plat |
|
|
Agriculture (volun. use
of BMPs endorsed by local SWCD); forestry (ES controls during & after
harvest); single family homes < 5,000 s.f. impervious (exempt (rate
control), must have ES control); roof runoff infiltration recommended (may be
req'd) |
|
|
Agriculture, mining,
single family homes not part of plat |
|
|
Agriculture, forestry,
single family homes w/ lots < 2 acres |
|
|
Agriculture, forestry |
|
|
Agriculture; projects
< 5,000 s.f. impervious; projects which collect stormwater from more than
5,000 sq. ft. drainage area |
|
|
Agriculture, forestry,
developments not contributing to downstream impacts |
|
|
Agriculture, forestry,
single family homes not part of plat |
|
Urban Drainage and Flood
Control District ( |
N/A - local governments
may have permitting programs |
|
|
Agriculture, forestry |
|
South Florida Water
Management District |
Agriculture using closed
water management systems |
|
Southwest Florida Water
Management District |
Agriculture (w/ site
specific Conservation Plan - appro. BMPs); forestry (complying with
"Florida Silviculture BMP Manual"); single family homes not in
subdivision |
|
Suwannee River Water
Management District |
Agriculture (with site
specific Conservation Plan with appropriate BMPs); forestry (comply w/
"Florida Silviculture BMP Manual"); single family homes not in
subdivision |
|
State of |
Agriculture (if using
Farm Conservation Plan prepared by local Soil and Water Conservation
District); forestry; single family homes; projects disturbing < 5,000 s.f. |
|
Florida Department of
Environmental Protection |
Agriculture (with site
specific Conservation Plan with appropriate BMPs); forestry (comply w/
"Florida Silviculture BMP Manual"); single family homes not in
subdivision |
|
Maryland Department of
the Environment |
Agriculture, single
family homes (min. lot size > 2 acres); developments which discharge to
tidewaters, served by storm drain system, or cause < 10% increase in peak
discharge rate (2 yr storm) |
|
State of |
Agriculture; forestry,
single family homes not part of larger development; developments which are
minor subdivision (< 2 lots) or disturb < 100 s.f. |
Continued
Table Stormwater 1.
Stormwater Management Program Exemptions and Waivers (Cont.)
|
Jurisdiction |
Exemptions
and Waivers |
|
State of |
Construction sties < 5
acres and not located; within ˝ mile of a water classified as a High Quality
Water, in a coastal county and draining to a saltwater or other classified
water, and located in a non-coastal county and draining to or within one mile
of a water classified as a High Quality Water or an Outstanding Resource
Water. |
|
State of |
Agriculture; forestry;
developments which have specified amount of impervious area (depending on
watershed) |
|
State of |
Agriculture, forestry,
single family homes not part of large development, utility operations with
certificate of environmental compatibility |
|
State of |
Single family homes not
part of larger development; agriculture; forestry; projects disturbing < 1
acre; mining & oil gas operations elsewhere permitted |
|
Washington State
Department of Ecology |
Agriculture, forestry
(except for forest conversions); activities disturbing < 1 acre; single
family homes |
Table Stormwater 2.
Stormwater Management Program Preferred Practices
|
Jurisdiction |
|
|
|
NONE, but developers use
non-land intensive practices |
|
|
Sedimentation/filtration
basins (stormwater quality); dry detention systems (flood control); wet
detention, retention/irrigation, filter strips. |
|
|
NONE, but require site
specific stormwater plan using appropriate BMPs (wet detention, swales,
filters, catch basin inserts, oil-water separators, coalescing plate
separators. NO INFILTRATION (slow perc soils w/ easy clogging). |
|
|
NONE |
|
|
Treatment hierarchy:
constructed wetlands for > 12 ac impervious; wet ponds & sand filters
for < 12 ac impervious; biofiltration for < 12 ac impervious; wet
detention vaults for < 2 ac impervious |
|
|
Off-line retention,
filtration, dry and wet detention |
|
|
NONE |
|
|
Infiltration preferred,
but sand filtration often used (less land req'd). Wet & dry detention,
swales, dry wells, rooftop detention, underground detention |
|
|
Retention |
|
|
Infiltration preferred
AND required when percolation rate > 0.17 in/hr. Extended dry detention,
wet detention, sand filters |
|
|
Infiltration basins or
trenches preferred (req'd in A and B soils); biofiltration swales, wet
detention ponds, filter strips, constructed wetlands, sand filters. |
|
|
Source controls including
forest retention & erosion control; treatment including grass swales, wet
detention ponds, filter strips, wet vaults |
|
|
Wet detention &
biofilt.; infiltration, ext. dry detention, const. wetlands, sand filtration |
|
|
Infiltration practices
since retention required for all new development |
|
|
Infiltration (when
feasible) & sand filters, in combination with dry detention, for
discharges to thermally sensitive waters; wet detention/wetland ponds or
extended detention in combination with other practices |
|
|
Infiltration, extended
dry or wet detention, bioretention, grit & oil separators |
|
|
Infiltration where
appropriate; filtration; biofiltration; wet detention |
|
|
Dry detention basins;
vegetated swales; wet detention ponds; constructed wetlands; infiltration NOT
ALLOWED |
|
|
None specified; swales,
extended dry detention, wetland ponds favored; infiltration NOT ALLOWED |
|
Urban Drainage and Flood
Control District ( |
Extended detention basins
& retention ponds; modular porous pavement; wetland basins & channels |
|
|
Extended detention
basins; swales, infiltration, vegetative buffers (esp. when combined with
detention) |
|
South Florida Water
Management District |
Retention, exfiltration
trenches, grass swales, wet detention ponds |
|
Southwest Florida Water
Management District |
Retention, exfiltration
trenches, pervious pavement, grass swales, wet detention, detention with
filtration, wetland systems; "BMP Treatment Train" encouraged |
|
Suwannee River Water Management
District |
Retention, exfiltration
trenches, pervious pavement, grass swales, wet detention, detention with
filtration, wetland systems; "BMP Treatment Train" encouraged |
Continued
Table Stormwater 2.
Stormwater Management Program Preferred Practices (Continued)
|
Jurisdiction |
Preferred Practices |
|
State of |
Wet detention ponds &
constructed wetlands; extended dry detention & sand filter; infiltration
(least preferred) |
|
Florida Department of
Environmental Protection |
Retention, exfiltration trenches,
pervious pavement, grass swales, wet detention, detention with filtration,
wetland systems; "BMP Treatment Train" encouraged |
|
Maryland Department of
the Environment |
Infiltration, swales,
retention, detention (preferred order) |
|
State of |
Extended detention; wet
ponds; permanent pools; infilt. basins; vegetative filters |
|
State of |
Preventive Measures
(nonstructural controls) |
|
State of |
None |
|
State of |
Wet detention, dry
detention, infiltration |
|
State of |
None, but regulations
have design criteria for detention, retention & infiltration |
|
Washington State
Department of Ecology |
Infiltration preferred;
pervious & modular pavement; grass swales; vegetated filters; extended
dry detention; wet detention ponds; constructed wetlands; sand filters |
Table Stormwater 3.
Stormwater Management Program Currently Used Practices
|
|
Infiltration Trench |
Filter |
Wet Detention Pond |
Extended Dry Detention
Pond |
Peak Detention Control |
Biofiltration |
Dry Wells |
Swales |
Wetlands |
Grit/Oil Separators |
Underground Detention |
|
|
|
1 |
2 |
6 |
3 |
2 |
|
|
|
|
|
|
|
|
|
|
|
100 |
4 |
4 |
120 |
|
|
|
|
|
|
|
|
|
|
1 |
|
8 |
|
13 |
|
|
|
|
|
|
|
10 |
10 |
|
20 |
|
20 |
40 |
|
|
|
|
|
|
|
|
|
10 |
|
2 |
|
|
72 |
|
|
|
|
|
|
|
|
|
35 |
|
|
150+ |
1000+ |
20 |
4 |
|
|
|
|
|
75 |
5 |
14 |
10 |
5 |
21 |
|
|
15 |
|
|
|
|
2 |
100 |
|
43 |
10 |
16 |
|
|
|
|
43 |
9 |
|
|
|
|
|
2 |
24 |
|
|
|
|
2 |
|
|
|
|
|
|
4 (compost) |
|
10 |
|
|
|
25 |
|
|
|
|
South Florida Water
Management District |
200 |
100 |
|
600 |
|
|
|
|
400 |
|
|
|
|
Southwest Florida Water
Management District |
1457 |
54 |
507 |
581 |
|
|
|
|
|
55 |
|
|
|
State of |
4-6 |
22 |
15-30 |
125-175 |
|
|
19-24 |
|
9-19 |
4 |
|
|
|
Florida Department of
Environmental Protection |
316 |
|
158 |
15 |
|
|
|
|
53 |
|
|
|
|
Maryland Department of
the Environment |
531 |
|
|
|
464 |
|
|
|
153 |
47 |
285 |
|
|
State of |
325 |
4 |
|
100 |
25 (+ 150 not extended) |
175 |
|
|
400 |
3 |
|
|
Table Stormwater 4.
Stormwater Management Program Water Quality Performance Standards
|
Jurisdiction |
|
|
|
New development - no net
increase in pollutant loading; Redevelopment - decrease loadings by 10%. |
|
|
No adverse water quality
impacts |
|
|
No specified standard |
|
|
None |
|
|
80% removal suspended
solids |
|
|
80% reduction average
annual total suspended solids loading |
|
|
No specified standard |
|
|
Oil & Grease < 10
mg/L; reduce organic waste by min. of 85% from confined animal operations |
|
|
80% reduction average
annual total suspended solids loading |
|
|
80% reduction average
annual total suspended solids loading |
|
|
No specified standard |
|
|
No specified standard |
|
|
No specified standard |
|
|
No specified standard |
|
|
Meet state water quality
standards |
|
|
Meet state water quality
standards |
|
|
No specified standard |
|
|
Treat 1.25 in (2 hr)
storm |
|
|
Remove 65% of total
phosphorus |
|
Urban Drainage and Flood
Control District ( |
Treat 80th percentile
runoff event volume |
|
|
Minimize adverse impacts |
|
South Florida Water
Management District |
80% reduction average
annual total suspended solids loading; compliance with state water quality
standards |
|
Southwest Florida Water
Management District |
80% reduction average
annual total suspended solids loading; compliance with state water quality
standards |
|
Suwannee River Water
Management District |
80% reduction average
annual total suspended solids loading; compliance with state water quality
standards |
|
State of |
80% reduction of annual
total suspended solids loading |
|
Florida Department of
Environmental Protection |
80% reduction of annual
total suspended solids loading |
|
Maryland Department of
the Environment |
No specified standard |
|
State of |
80% reduction of total
suspended solids |
|
State of |
85% removal of total
suspended solids (TSS) |
|
State of |
No specified standard |
|
State of |
80% reduction of annual
total suspended solids loading |
|
State of |
No specified standard
(draft proposed) |
|
Washington State
Department of Ecology |
No specified standard |
Table Stormwater 5.
Stormwater Management Program Water Quality Design Criteria
|
Jurisdiction |
|
|
|
Treat 1st 1/2 inch of
runoff from impervious surfaces using appropriate BMPs. |
|
|
Sedimentation/filtration
to treat min. 1/2" + 0.1" for each 10% increase in impervious area
above 20%; WITHIN BARTON SPRINGS ZONE - No increase in pollutant loading for
13 parameters listed in Save Our Springs Ordinance |
|
|
Treat runoff from 6 month
(24 hr.) storm using appropriate BMPs. |
|
|
None |
|
|
Treat runoff volume of 6
month (24 hr) storm |
|
|
Treat greater of: 1st 1/2 inch of runoff or runoff from 1st
inch of rainfall |
|
|
Treat runoff from 6 month
(24 hr.) storm |
|
|
Treat 1st 1/2 inch of
runoff or difference in runoff volume from 15 yr (post-development) and 2 yr
(pre-development) storms |
|
|
Treat 1st inch of runoff
by retention |
|
|
Treat 1st 1/2 inch of
runoff from impervious surfaces using appropriate BMPs. |
|
|
Treat runoff from 6 month
(24 hr) storm with appropriate BMPs |
|
|
Treat 1/3 of runoff from
2 yr (24 hr) storm |
|
|
Treat runoff from 6 month
(24 hr) storm per WDOE requirements |
|
|
Follow state NPDES
regulations |
|
|
Treat 1st 1/2 inch of
runoff using appropriate practices |
|
|
Treat 1st 1/2 inch of
runoff using appropriate practices |
|
|
Treat post-development
runoff from 6 month (24 hr) storm with appropriate BMPs |
|
|
Discharge 90% total
inflow volume within 18 hr (SF resid.) or within 36 hrs (MF resid. or
non-resid.) |
|
|
Treat 0.36 in of runoff
(4 hr storm) from new impervious using appropriate BMPs |
|
Urban Drainage and Flood
Control District ( |
Treatment volume depends
on imperviousness & detention time - max. value for 100% impervious is
0.5 in runoff. |
|
|
Depends on treatment
practice: 6 mo storm for swales &
runoff from 2 in storm for other practices |
|
South Florida Water
Management District |
Treatment volume varies
from 1.0 in to 2.5 in times % impervious area; dry pretreatment required for
discharge to sensitive waters |
|
Southwest Florida Water Management
District |
Treatment volume varies
from 0.5 in to 1.5 in, depending on practice used, receiving water type, amt.
Impervious surface |
|
Suwannee River Water
Management District |
Treatment volume varies
from 0.5 in to 2.0 in, depending on practice used, receiving water type, amt.
Impervious surface |
|
State of |
Treat 1st inch of runoff
by approved BMPs |
|
Florida Department of
Environmental Protection |
Treatment volume varies
from 0.5 in to 1.5 in, depending on practice used, receiving water type, amt.
Impervious surface |
|
Maryland Department of
the Environment |
Manage difference between
post-development & pre-development rate for 2 yr & 10 yr storms |
Continued
Table Stormwater 5.
Stormwater Management Program Water Quality Design Criteria (Continued)
|
Jurisdiction |
Water Quality Design Criteria |
|
State of |
Manage storm > 1.25
in. in 2 hrs or 1 yr (24 hr) storm with release outflow of 90% of volume w/in
18 hrs (resid.) & w/in 36 hrs (non-resid.) |
|
State of |
Varies with proximity to
and the classification of the receiving water and also may be determined by
local rules |
|
State of |
Some municipalities
requires practices |
|
State of |
Treatment volume varies
from 0.5 in (wet ponds) to 1 in (dry detention, retention) with drawndown
w/in 24 hrs |
|
State of |
Treat 0.5 in runoff from
project area; detention basins release over 30 hours; infiltration must
percolate w/in 48 hrs; retention basins must have permanent pool 3 times
greater than treatment volume |
|
Washington State
Department of Ecology |
Treat runoff from 6 month
(24 hr) storm using BMPs appropriate for site |
Table Stormwater 6.
|
Jurisdiction |
|
|
|
No increase in
rate. |
|
|
No increase in peak
rate, no increase in streambank erosion. |
|
|
100 year storm
protection |
|
|
Depending on basin,
can require detention with no increase in rate |
|
|
No increase in
rate. |
|
|
No increase in
rate. |
|
|
No increase in
rate. |
|
|
No increase in peak
rate. |
|
|
None - rely on
SJRWMD requirements |
|
|
No increase in
rate. |
|
|
No specified
standard |
|
|
Base protection
standard & stream protection standard |
|
|
No specified
standard |
|
|
No increase in
velocity & peak rates of washes |
|
|
No specified
standard |
|
|
No increase in
rate. |
|
|
No increase in
rate. |
|
|
Performance
standards set by county watershed models |
|
|
No increase in
rate. |
|
Urban Drainage and
Flood Control District ( |
Performance
standards depend on storm and location |
|
|
No increase in
rate. |
|
South Florida Water
Management District |
No adverse impacts |
|
Southwest Florida
Water Management District |
No adverse impacts |
|
Suwannee River
Water Management District |
No adverse impacts |
|
State of |
No increase in
rate. |
|
Florida Department
of Environmental Protection |
None - set by local
government |
|
Maryland Department
of the Environment |
No specified
standard |
|
State of |
Match
pre-development conditions; non-erosive |
|
State of |
Varies with proximity to
and the classification of the receiving water and also may be determined by
local rules |
|
State of |
Performance
standard set in local watershed plan |
|
State of |
No increase in
rate. |
|
State of |
No increase in
rate. |
|
Washington State
Department of Ecology |
No specified
standard; minimize bank erosion |
Table Stormwater 7.
|
Jurisdiction |
Peak
Discharge Design Criteria |
|
|
Post-development peak
rate less than or equal to pre-development rate for 2-yr. & 10-yr. (2
hr.) storm |
|
|
Post-development rate
< pre-development for 2, 10, 25, 100-yr (24 hr) storm |
|
|
< 5 ac. ŕ <0.2 cfs/acre; > 5
ac. ŕ post-development <=
pre-development for 2 yr & 10 yr (24 hr.) storm |
|
|
Post-development rate for
100 yr (1 to 3 hr) storm < historic 2-yr (1 to 3 hr) storm |
|
|
Post-development rate not
exceed pre-development for 2 yr & 100 yr (24 hr) storm. Max. release
rates 0.04 cfs/acre (2-yr) & 0.35 cfs/acre (100 yr) |
|
|
Post-development peak
rate < pre-development rate for 25-yr (24 hr) storm |
|
|
< 0.2 cfs/acre for 25
yr (24 hr) storm for < 9,000
s.f.; < 15 cfs/acre for 2 yr (24
hr) storm for > 9,000 s.f. |
|
|
Post-development <
pre-development rate for 2 yr, 10 yr, & 100 yr (24 hr) storms |
|
|
Post-development rate
< pre-development rate for 25 yr (24 hr) storm |
|
|
Post-development rate
< pre-development rate for 2 yr & 10 yr (24 hr) storms |
|
|
Post-development <
pre-development rate for 2 yr, 10 yr, & 100 yr (24 hr) storms |
|
|
Base protection:
post-development rate < pre-development rate for 2 yr & 10 yr storm;
stream protection: post-development rate < pre-development rate for 100 yr
storm; control duration for 2 to 50 yr storm |
|
|
Post-development rate
< 50% of pre-development rate for 2 yr (24 hr) storm, &
pre-development rate for 10 yr & 100 yr (24 hr) storms [SBUH analysis] |
|
|
Site specific analysis
required. |
|
|
Post-development <
pre-development rate for 2 yr (24 hr) storm & when necessary, for 10 yr
& 100 yr (24 hr) storm |
|
|
Post-development peak
rate < pre-development rate for 2 yr & 10 yr (24 hr) storms, & for
100 yr (24 hr) storm if downstream flooding potential |
|
|
Post-development <
pre-development rate for 10 yr & 100 yr (24 hr) storm; if no
infiltration, rate of detained volume release < 50% of pre-development
rate |
|
|
Post-development rate
< percentage of pre-development rate: 2 yr storm (50%); 10 yr storm (75%);
100 yr storm (80%) |
|
|
Post-development <
pre-development rate for 25 yr (24 hr) storm |
|
Urban Drainage and Flood
Control District ( |
Post-development peak
rate for 2 yr, 5 yr, 10 yr, 50 yr, 100 yr storm < historic (undeveloped)
rate for 5 yr & larger storms |
|
|
Post-development <
pre-development rate w/ max. 0.15 cfs for 100 yr (24 hr) storm |
|
South Florida Water
Management District |
Post-development <
pre-development rate for 25 yr (3 day) storm (unless downstream designed for
higher rate) |
|
Southwest Florida Water
Management District |
Post-development <
pre-development rate for 25 yr (24 hr) storm |
|
Suwannee River Water
Management District |
Post-development <
pre-development rate for critical duration storm (storm up to 100 yr (24 hr)
that produces greatest change) |
Continued
Table Stormwater 7.
|
Jurisdiction |
Peak
Discharge Design Criteria |
|
State of |
Post-development <
pre-development rate for 2 yr & 10 yr (24 hr) storms; northern 20% of
state - same control for 100 yr (24 hr) storm |
|
|
Post-development <
pre-development rate for 10 yr to 25 yr (24 hr) storm |
|
Maryland Department of
the Environment |
Post-development rate
< pre-development rate for 2 yr & 10 yr storms |
|
State of |
Post-development rate
& volume < pre-development rate & volume for 2 yr, 10 yr, &
100 yr (24 hr) storm |
|
State of |
Varies with proximity to
and the classification of the receiving water and also may be determined by
local rules |
|
State of |
Level of control (design
& rate) established by local gov. in its watershed plan |
|
State of |
Post-development <
pre-development rate for 2 yr, 25 yr (24 hr) storm; must pass 100 yr (24 hr)
storm |
|
State of |
Post-development <
pre-development rate for 2 yr & 10 yr storms; duration is 24 hr storm
(SCS Method) or critical storm (Rational Method) |
|
Washington State
Department of Ecology |
Post-development < 50%
pre-development rate for 2 yr (24 hr) storm; post-development <
pre-development rate for 10 yr & 100 yr (24 hr) storm |
Table Stormwater 8.
Stormwater Management Program Volume Performance Standards
|
Jurisdiction |
Volume
Performance Standards |
|
|
None |
|
|
None |
|
|
100 year storm protection |
|
|
None |
|
|
Maintain 100 year volume
on site |
|
|
In closed basins |
|
|
None |
|
|
None |
|
|
None |
|
|
None |
|
|
Maintain groundwater
recharge; maintain existing flows & levels in downstream channels |
|
|
None - under study |
|
|
Only for certain
downstream waters |
|
|
No increase allowed
(flood prevention) |
|
|
None |
|
|
None |
|
|
No specified standard |
|
|
Offset increased runoff
volumes and flow durations that create or add to channel erosion |
|
|
None |
|
Urban Drainage and Flood
Control District ( |
None |
|
|
Minimize increases to
lessen downstream flooding, enhance recharge & base flow |
|
South Florida Water
Management District |
No increase in rate;
maintain ground water recharge & downstream baseflow |
|
Southwest Florida Water
Management District |
In closed basins, no
increase for design storm |
|
Suwannee River Water
Management District |
No net increase in flood
storage |
|
State of |
No specified standard |
|
Florida Department of
Environmental Protection |
None - set by local
government (rare except in closed basin) |
|
Maryland Department of
the Environment |
No specified standard |
|
State of |
Approximate
pre-development hydrology (proposed) |
|
State of |
Varies with proximity to
and the classification of the receiving water and also may be determined by
local rules |
|
State of |
No specified standard |
|
State of |
None |
|
State of |
No specified standard |
|
Washington State
Department of Ecology |
No specified standard;
goal to recharge aquifer, maintain baseflows |
Table Stormwater 9. Stormwater
Management Program Volume Design Criteria
|
Jurisdiction |
|
|
|
None |
|
|
None |
|
|
For detention systems, require
multiple release rate |
|
|
None |
|
|
Infiltrate all of 100-yr volume if
percolation rate on-site > 6 in/hr. Between 0.5 & 6 in/hr, must
infiltrate part of volume |
|
|
Retain runoff from 100 yr (24 hr)
storm |
|
|
None |
|
|
None |
|
|
None |
|
|
None |
|
|
Post-development < pre-development
volume for 2 yr (24 hr) storm; post-development < pre-development volume
for 10 yr & 100 yr (24 hr) storms for downstream channels |
|
|
None |
|
|
Post-development < pre-development
volume for 100 yr (7 day) storm using SBUH analysis |
|
|
Retain runoff volume from 100 yr (2
hr) storm |
|
|
None |
|
|
Infiltration required if soil
percolation rate > 0.17 in/hr |
|
|
Infiltrate runoff from 2 yr (24 hr)
storm to extent site conditions allow |
|
|
Reduce 2 yr peak rate by 50% |
|
|
None |
|
Urban Drainage and Flood Control
District ( |
None |
|
|
Promote minimizing imperviousness
& maximizing infiltration |
|
South Florida Water Management
District |
Post-development < pre-development
volume for all storms up to 100 yr (24 hr) storm |
|
Southwest Florida Water Management
District |
Post-development < pre-development
volume for all storms up to 100 yr (24 hr) storm |
|
Suwannee River Water Management
District |
Post-development < pre-development
volume for all storms up to 100 yr (24 hr) storm |
|
State of |
None |
|
Florida Department of Environmental
Protection |
Post-development < pre-development
volume for 25 yr to 100 yr (24 hr) storm |
|
Maryland Department of the
Environment |
None |
|
State of |
Post-development 2-yr peak = 50% of
pre-development; post-development 10 yr & 100 yr peak = 75% existing |
|
State of |
May be set by watershed plan |
|
State of |
None |
|
State of |
None |
|
Washington State Department of
Ecology |
Infiltrate runoff from 2 yr (24 hr)
storm to extent site conditions allow |
Table Stormwater 10. Stormwater
Management Program Source Controls
|
Jurisdiction |
|
|
|
Developing Non-Structural BMP
Handbook for Auto-Related Businesses (pub. 1995) |
|
|
“Save Our Springs” ordinance requires
all land uses within Barton Springs to use source controls including limits
on turf grass & landscaped areas, integrated pest management, chemical
storage restrictions, homeowner education packets (lawn care, pest treatment,
recycling, household waste disposal, general watershed information) |
|
|
Encouraged esp. for construction and
gasoline-related and food-related activities. |
|
|
Encouraged in city’s NPDES MS4 permit
proram. Favor pollution prevention for all land uses. Passive treatment
methods incorp. Into master planned drainages to promote habitat protection. |
|
|
Encouraged for all land uses;
maintenance plans inc. pollution source control for site. Encourage roofing
operations or storage areas, placing berms around barrel for secondary
containment, directing wash water to sanitary sewer, proper disposal, good
housekeeping |
|
|
Encouraged on all land uses. |
|
|
Enc. All land uses; inspect comm.
& indust. Business served by sep. storm sewers; Enc. Roofing for storage
areas, berms around barrels for sec. Contain., directing wash water to
sanitary sewer, proper waste disposal, good housekeeping (esp. around outside
dumpsters) |
|
|
Oil recycling, good housekeeping,
street sweeping, natural system conservation – all land uses |
|
|
Good housekeeping, landscaping,
eduction on commercial and multifamily residential projects |
|
|
Encouraged all land uses; rec. limit
imperviousness & using buffers to protect streams & wetlands |
|
|
Recomm. Specific land uses, inc.
manu., transp. & communication, wholesale/retail sales, service business,
public land activities; inc. fuel station, vehicle/equip. wash areas,
storage/loading of solid/liquid mat’l, veg. Mgmt practices. |
|
|
Enc. All land uses – urban (citizen
& business education); agriculture (density limits on livestock &
limit animal access to streams); construction (clearing limits in wet season) |
|
|
Recomm. Manu., transp. & commun.,
wholesale/retail sales, service business, public land activity; inc. fuel
station, vehicle/equip. wash areas, storage/loading of materials, vegetative
mgmt |
|
|
Pollution prevention plans that
emphasize general housekeeping & using less toxic materials |
|
|
Gen. Public info.; edu. Re: proper
use of fertilizers/pesticides, proper disposal of oil, antifreeze, &
other haz wastes; practices to imp. Health of riparian zones (esp. in
proposed special protection areas) |
|
|
As required by County’s NPDES
municipal storm sewer system permit. |
|
|
Encouraged for commercial and
industrial land uses; inc. mat’l handling, roofing, proper plumbing |
|
|
Encouraged for all land uses. Include
material protection & storage, spill prevention & clean-up,
fertilizer & pesticide use & management |
|
|
Encourage 25 ft wide buffers – stream
corridors & wetlands (new developments); cover prac. Emph. |
|
Urban Drainage and Flood Control
District ( |
Encouraged all land uses; inc.
minimizing DCIA, grass buffers, swales, good housekeeping practices |
|
|
Encouraged for all land uses |
|
South Florida Water Management
District |
Dry pretreatment for industrial &
commercial land uses; no discharges of industrial waste or hazardous &
toxic substances into stormwater system |
|
Southwest Florida Water Management
District |
Agriculture has site specific farm
plan with appropriate BMPs; BMPs include irrigation management, nutrient
& pesticide management, field layout, wetland avoidance, buffers. |
|
Suwannee River Water Management
District |
Indust. & comm.; no disch. Indus.
Waste, haz or toxic substance in storm sewer; contain. Plans req’d |
Continued
Table Stormwater 10. Stormwater
Management Program Source Controls (Continued)
|
Jurisdiction |
Source Controls |
|
|
Encourage poll. prev. source
controls; emph. educ. for students, citizens, businesses, elected officials,
& practitioners - stress interrelationships & how to abate
"Pointless Personal Pollution." |
|
State of |
Site plan/design; nat. feature
preserve; min. disturbance/impervious cover; nat. landscape;
fertilizer/pesticide controls; haz waste collection |
|
State of |
Encouraged for agricultural
activities; include tillage practices, animal waste/ nutrient management |
|
State of |
Encourage for truck stops, indust.,
large comm., multi-family resid.; inc. cover loading docks & other handling areas; street sweep (inc.
parking); dry cleaning trash handling areas; sequencing const. |
|
State of |
Enc. alt. to struct. controls; inc.
cluster devel., min. imperv. surf. & curbs, open space acquisition,
floodplain mgmt, wetlands & steep slope prot., vegetation |
|
Washington State Department of
Ecology |
Recomm. specific land uses, inc.
manu., transp. & comm., wholesale/retail sales, service business, public land activity; inc. fueling
stations, vehicle/equip. wash areas, storage/loading, vegetative mgmt |
Table Stormwater 11. Stormwater
Management Program Other Requirements
|
Jurisdiction |
Other
Requirements |
|
|
Downstream evaluation required for
protection of downstream channel stability. |
|
|
Downstream evaluation required for
protection of downstream channel stability. |
|
|
Downstream evaluation required with
maximum velocity specified to assure downstream channel stability |
|
|
Downstream evaluation required for
discharges to master planned facilities. No criteria for downstream channel
stability |
|
|
Downstream evaluation required with
maximum velocity specified to assure downstream channel stability |
|
|
Downstream evaluation required for
protection of downstream channel stability. |
|
|
Downstream evaluation required with
maximum velocity specified to assure downstream channel stability |
|
|
Downstream evaluation required for
protection of downstream channel stability. |
|
|
Lakefront residential units must
direct runoff to pervious areas. Downstream evaluation NOT REQUIRED to assure
protection of downstream channel stability. |
|
|
Downstream evaluation required for
suitable outfall and downstream channel stability. |
|
|
Downstream evaluation of capacity
required if pre-development runoff calculations do not assume undisturbed
forest in determining runoff curve number. |
|
|
Downstream evaluation required for
min. Ľ mile or 15% of drainage system w/ downstream channel stability
required when stream protection standard applies |
|
|
Downstream evaluation required for at
least Ľ mile with downstream channel stability evaluated; flooding &
water quality impacts evaluated |
|
|
Downstream evaluation required for
any off-site discharges (prevent increase in downstream flooding potential);
Downstream channel stability evaluation required where potential problem
exists. |
|
|
Downstream evaluation required for downstream
channel stability |
|
|
Downstream evaluation required for
downstream channel stability |
|
|
Downstream evaluation required for
downstream channel stability |
|
|
Downstream evaluation required for
downstream channel stability |
|
|
Downstream evaluation required to
prevent increase in downstream flooding potential with detention or increased
conveyance capacity used as mitigation; no evaluation of channel stability
required. |
|
Urban Drainage and Flood Control
District ( |
Downstream evaluation may be
required, esp. if no master plan for area; downstream channel stability
required using grade control or bank erosion control |
|
|
Downstream evaluation recommended; 2
yr storm peak discharge rate of 0.04 cfs/acre to minimize channel erosion |
|
South Florida Water Management
District |
Downstream evaluation required for
natural systems (downstream channel stability) |
|
Southwest Florida Water Management
District |
Downstream evaluation required for
downstream channel stability |
|
Suwannee River Water Management
District |
Downstream evaluation required for
downstream channel stability |
|
|
Downstream evaluation required for
downstream channel stability |
Continued
Table Stormwater 11. Stormwater
Management Program Other Requirements (Continued)
|
Jurisdiction |
Other
Requirements |
|
Maryland Department of the
Environment |
Downstream evaluation required for
downstream channel stability |
|
State of |
Downstream evaluation required for no
increase in peak velocities & downstream channel stability |
|
State of |
Downstream evaluation may be required
by local government |
|
State of |
Downstream evaluation required with
maximum velocity specified to assure downstream channel stability |
|
State of |
Downstream evaluation NOT required,
but discharge must not cause instability of downstream channel |
|
Washington State Department of
Ecology |
Downstream evaluation required for
downstream channel stability; stream channel erosion BMPs must have
correction factor which ranges from 20 to 50% of design volume depending on
amount of impervious surface |
Table Stormwater 12. Stormwater Management
Program Publications
|
Jurisdiction |
|
|
|
City's Supplement to the |
|
|
Environmental Criteria Manual;
Guidance for Compliance with the Technical Requirements of the SOS Ordinance |
|
|
BP How To Manual; Water Quality
Protection for Bellevue Business; Consumer Choices - Car Care, Lawn &
Garden Care, Home & Bldg. Maintenance; Business Partners, Storm Drain
Stenciling Brochure; Stream Team Guidebook or Brochure; IPM Notebook |
|
|
|
|
|
|
|
|
|
|
|
City of |
|
|
Oil Recycling; The D.C. Urban
Homeowner's Guide on Ground Maintenance |
|
|
County ordinances; Stormwater
Management Manual for the |
|
|
Ordinance, Stormwater Program booklet
& brochure, Stormwater Management Manual for the |
|
|
Arizona NPDES stormwater regulations;
Drainage Design Manual for |
|
|
|
|
|
County Stormwater Management Design
Manual, 1991; Design Manual for Use of Bioretention in Stormwater Management,
1993; pamphlets on lawn care, car care, etc. |
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State of the Waters: 1993 Assessment;
Stormwater Characterization and Pollution Load Estimattes (May 1994); 1993-94
Watershed Education Program Final Report and Evaluation (Sept. 1994);
Stormwater Management Manual for the |
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Source controls, fertilizer, &
pesticide use by residents. |
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Erosion Control Plans Technical
Guidance Handbook; Portland/USA Water Quality Facilities Technical Guidance
Handbook; King County Hydrology/Hydraulics Method Handbook |
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Urban Drainage and Flood Control
District ( |
Urban Storm Drainage Criteria Manual,
Volumes 1 and 2 (rev. 1991); Urban Storm Drainage Criteria Manual, Volume 3 -
BMPs (1992) |
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Model Stormwater Drainage and
Detention Ordinance; Urban Stormwater Best Management Practices for |
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South Florida Water Management
District |
Management and Storage of Surface
Waters, Part IV, Applicant's Handbook |
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Southwest Florida Water Management
District |
Management and Storage of Surface
Waters, Part IV, Applicant's Handbook |
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State of |
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Florida Department of Environmental
Protection |
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State of |
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State of |
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State of |
A Guide to Site Development and Best
Management Practices for Stormwater Management and Sediment Control; |
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State of |
Stormwater Management Handbook
(available January 1996) |
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Washington State Department of
Ecology |
Stormwater Management Manual for the |
The following is a summary of some of the current statewide stormwater management programs.
Stormwater permits in
The Arkansas Department of
Pollution Control and Ecology publishes guidance for detention ponds and
erosion control. If a study of a proposed
development indicates flooding problems, a development permit would be denied
without stormwater control. Examples of
acceptable controls are on-site storage, off-site storage or an improved
drainage system. The method used for
stormwater detention is the modified rational hydrograph method. This guidance includes tables and graphs for
determining time of concentration and rain intensity. The required volume of detention is evaluated
according to the following methods (Contractor’s Guidance):
A.
Volume of detention
for projects of less than 50 acres shall be evaluated by the ‘simplified volume
formula’.
B.
Volume of detention
for projects 50 acres or greater but less than 200 acres may be evaluated
either by the “simplified volume formula” or the “modified rational hydrograph
method”.
C.
For projects larger
than 200 acres, the owner’s engineer shall submit a proposed method of
evaluation for the sizing of the retention basin or detention basin to the
Department Public Works. The method will
be evaluated for a professional acceptance, applicability and reliability by
the City Engineer. No detail review for
projects larger than 200 acres will be rendered before the method of evaluation
of the retention or detention basin is approved.
D.
Other analytical
methods of evaluation of volume of detention require approval by the City
Engineer.
E.
NPDES permitting authority has
been delegated to the state of
The
Controls that may be required for
specific projects include grass drainage swales, percolation ponds, wet
detention ponds with filtration, and wetland treatment.
The Georgia Erosion and Sediment
Control Act of 1975 requires that a permit be obtained for many land disturbing
activities. These permits examine specific development and erosion control
plans but were not required to specifically address stormwater quality
controls.
Local governments can adopt
ordinances to enforce this law, but the State's Environmental Protection
Division of the Georgia Department of Natural Resources will have permitting
and enforcement responsibilities if no local regulations are passed. However,
local review of erosion control plans by the regional Soil and Water
Conservation District must be provided. The Natural Resources Conservation
Service (NRCS) is commonly asked to provide technical assistance in these
reviews.
Monitoring requirements are
outlined for industrial dischargers. Stormwater pollution control plans
(SWPCP’s) must be developed and implemented by industrial dischargers. These SWPCP’s parallel the U.S. EPA’s basline
SWPCP’s.
|
Land Use Activity |
Agency of Local
Function |
Permit,
Approved Process, or Authority |
Type of
Construction |
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Plan Review |
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Storm Water Pollution Prevention
Plan Review (optional at local level) |
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National Pollutant Discharge
Elimination System (NPDES) discharge permits |
industrial, commercial and
residential over 5 acres |
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Drainage Plan review |
Local public works or building
department |
Consult local authority |
commercial, residential |
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Storm Water Discharges |
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To a right-of-way |
Local or county highway district |
Consult local authority |
industrial, commercial,
residential |
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To a natural waterway |
EPA and/or local/watershed-based
authority |
NPDES discharge permit |
industrial, commercial,
residential |
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To a privately-owned canal or
drain |
Local canal or drainage district
or EPA |
Permission from local canal
company or drainage district, NPDES discharge permit |
industrial, commercial,
residential |
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To a Bureau of Reclamation (BOR)
canal |
BOR, EPA |
Permission from BOR, NPDES
discharge permit |
industrial, commercial,
residential |
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From selected industrial
facilities |
EPA |
NPDES stormwater discharge
permit |
Industrial |
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Storm Water Disposal |
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To subsurface through an
injection well |
Idaho Department of Water
Resources (IDWR) regional office |
Underground Injection Control
(UIC) Program |
Industrial, commercial,
residential |
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Site Preparation/Construction |
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All new development/
redevelopment |
Local public works or building
department |
Local or county ordinance(s) |
commercial, residential |
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Construction over 5 acres |
EPA |
NPDES stormwater permit |
industrial, commercial,
residential |
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Development project potentially
impacting an existing highway |
Idaho Transportation Department,
Local or county highway district |
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industrial, commercial,
residential |
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Development project potentially
impacting an existing drainage facility |
Local public works or building
department, Canal company, Drainage district |
Local or county ordinance(s) |
industrial, commercial,
residential |
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Dewatering |
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Discharges to right-of-way |
Local or county highway district |
Consult local authority |
industrial, commercial,
residential |
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Discharge to a privately-owned
canal or drain |
Local canal company, Drainage
district |
Permission form canal company or
drainage district, NPDES discharge permit |
industrial, commercial,
residential |
|
Land Use Activity |
Agency of Local
Function |
Permit,
Approved Process, or Authority |
Type of
Construction |
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Other Permits |
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Stream Channel Alteration |
IDWR |
Stream Channel Alteration Permit |
industrial, commercial,
residential |
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Filling of wetlands other
natural waterways of the |
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404 (dredge and fill) permit |
industrial, commercial,
residential |
Source: Catalog of Storm Water Best Management Practices for
NPDES permitting authority has
been delegated to the state of
.
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Project Location/Type |
Standards |
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Watershed of a lake not most at
risk. Project with <3 acres of impervious area or Ł 5 acres of disturbed area |
Basic Stabilization Standard |
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Watershed of a lake most at risk
(severely blooming lake) |
Basic Stabilization Standard and
Phosphorous Standard |
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Watershed of a lake most at risk
(Not severely blooming lake) Project with ł 3 arces of disturbed area |
Basic Stabilization Standard and
Phosphorous Standard |
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Watershed of a lake most at risk
(Not severely blooming lake) Project with <3 acres of impervious area and
<5 acres of disturbed area |
Basic Stabilization Standard and
80% TSS Standard or Basic Stabilization Standard and
Phosphorous Standard |