MPCA Infiltration Device - Pond Requirements

The use of stormwater infiltration has been a popular choice for stormwater management for many years. The benefits of infiltration include reducing overall run-off volume, reducing stormwater and channel run-off rates, and reducing pollutant loading.

However, infiltration can also create other issues, including groundwater contamination. Infiltration of stormwater (and the wastes it carries) may also invoke other environmental regulations.

The Minnesota Pollution Control Agency has incorporated requirements for the use of both infiltration devices and stormwater ponds used to manage industrial site runoff. These requirements include:

1. Industrial stormwater ponds and infiltration devices located in areas where high levels of contaminants exist in the soil or in the shallow aquifer, must not contribute to contaminant(s) spreading to a greater extent or rate. At any contamination site, a site analysis shall be conducted and a report filed with the SWPPP.

a. If industrial stormwater ponds and infiltration devices are found to be a contributor to contaminant increase or movement, the site must submit a plan to MPCA that describes how they will be reducing contaminants, redesigning, relocating, or eliminating the industrial stormwater ponds and infiltration devices, as needed, to eliminate the contribution to contaminant problems.

2. Industrial stormwater ponds and infiltration devices can not be used in any high risk karst area unless a professional geotechnical evaluation is conducted to ensure that they do not present a significant risk to groundwater.

a. If the industrial stormwater ponds and infiltration devices present a risk, appropriate measures, such as sealing or removal of the industrial stormwater ponds or infiltration devices, must be taken to eliminate or minimize the risk. Evaluations shall be documented with the SWPPP.

3. Use of industrial stormwater ponds and infiltration devices in vulnerable wellhead protection areas must be coordinated with local drinking water authorities and shall be designed to not adversely affect drinking water supplies. The facility must contact the appropriate local drinking water authorities and document coordination efforts with the SWPPP.

4. Facilities using any infiltration device defined as a “Class V injection well” shall contact the US EPA Region HQ to determine the need to register as a “Class V injection well”. Contacts and USEPA response need be documented with the SWPPP.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address Stormwater Permitting & Regulatory Support, Stormwater Pollution Prevention Plans (SWPPP), Stormwater Monitoring and Stormwater Training.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Technical Guidance For EISA Section 438 Compliance

Under the new Section 438 of the Energy Independence and Security Act of 2007 (EISA), federal agencies have new requirements to reduce stormwater runoff from federal development and redevelopment projects to protect water resources. Federal agencies can comply using a variety of stormwater management practices often referred to as "green infrastructure" or "low impact development" practices, including for example, reducing impervious surfaces, using vegetative practices, porous pavements, cisterns and green roofs.

US EPA has recently issued guidance ("Technical Guidance on Implementing the Stormwater Runoff Requirements for Federal Projects under Section 438 of the Energy Independence and Security Act") to assist federal agencies in minimizing the impact of federal development projects on nearby water bodies. The guidance is being issued in response to a change in law and an Executive Order signed by President Obama, which calls upon all federal agencies to lead by example to address a wide range of environmental issues, including stormwater runoff.

The purpose of the guidance document is to provide technical guidance and background information to assist federal agencies in implementing EISA Section 438. Each agency or department is responsible for ensuring compliance with EISA Section 438. The document contains guidance on how compliance with Section 438 can be achieved, measured and evaluated.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address Stormwater Permitting & Regulatory Support, Stormwater Pollution Prevention Plans (SWPPP), Stormwater Monitoring and Stormwater Training.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

New Airport Deicing Fluid Regulations - Requirement to Collect and Treat

U.S. Environmental Protection Agency has proposed regulations requiring airports to collect at least some of the deicing fluid after it is used on aircrafts with a goal of cutting chemical discharge by 22%. The regulations would require six of the 14 major U.S. airports that are the biggest users of deicing fluid to install deicing pads or other collection systems to capture 60% of fluid sprayed and to install deicing pads or other collection systems. Some of the targeted airports include:

• New York's John F. Kennedy and LaGuardia airports,
• Chicago's O'Hare,
• Boston Logan International,
• Cleveland-Hopkins International, and
• New Jersey's Newark Liberty International

It would then be the airports' responsibility to ensure that the collected fluid was treated and handled in accordance with requirements. Some 200 smaller facilities around the US would have to collect 20 percent of the fluid by using technologies such as a glycol recovery vehicle, while airports with fewer than 1,000 yearly jet departures would not be impacted.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address Stormwater Permitting & Regulatory Support, Stormwater Pollution Prevention Plans (SWPPP), Stormwater Monitoring and Stormwater Training.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Massachusetts DEP Proposed Stormwater Regulations

The Massachusetts Department of Environmental Protection (DEP) is proposing a new approach to stormwater management which will require private owners of large impervious surfaces (including institutions, commercial, industrial and residential properties) to manage stormwater. The draft requirements include:

• Statewide private property owners of impervious surfaces ≥5 acres will be required to implement good housekeeping practices,
• Statewide private new developments with impervious surfaces ≥5 acres will be required to meet the state’s Stormwater Standards 3-6, including recharge and water quality treatment,
• Redevelopments with impervious surfaces ≥5 acres must maintain the same level of stormwater control and recharge, to the extent site constraints allow.

In areas that drain to an impaired waters with an existing or pending TMDL, a 65 % reduction in phosphorus load is required to achieve compliance with the State’s water quality standards.

Private property owners of impervious surfaces ≥2 acres will also be have requirements under the new program. New projects and redevelopments will have to meet statewide requirements and implement stormwater Best Management Practices (BMPs) capable of reducing phosphorus. Existing properties will be given 10 years to retrofit their properties to meet the phosphorus reduction requirement. TMDL areas include the Charles River watershed (with a 65% phosphorus reduction requirement) and a number of lake watersheds across the state.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address Stormwater Permitting & Regulatory Support, Stormwater Pollution Prevention Plans (SWPPP), Stormwater Monitoring and Stormwater Training.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

WDNR Runoff Standards - Proposed Amendment to NR 151

The Wisconsin Department of Natural Resources (WDNR) is currently in the process of making revisions to Wisconsin Rule NR 151. NR 151establishes runoff pollution performance standards for non−agricultural facilities and transportation facilities and performance standards and prohibitions for agricultural facilities and practices designed to achieve water quality standards.

The WDNR has proposed amendments that include:

• develop an agricultural buffer or equivalent performance standard and a performance standard to address sediment, manure and other runoff from smaller, non-permitted farms;
• modify post-construction non-agricultural performance standards, regarding infiltration and protective areas;
• revise existing agricultural performance standards and prohibitions to clarify provisions related to manure storage facility closures and direct runoff of manure; and
• modify grant rules pertaining to eligibility, awards, allocation for TMDLs and project size.

A formal proposal for amendments is expected to be released for public comment in 2009.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Stormwater Management Improvement Projects Funded Through Federal Stimulus

The Iowa State Revolving Fund (SRF) is currently soliciting "green projects" to be funded the SRF in response to the recent Federal Stimulus Bill. The federal stimulus bill routes some of the funds for water quality through the State Revolving Fund programs. Iowa’s allocation is $53 million for Clean Water SRF and $24 million for Drinking Water SRF. About 20% of each amount is intended to be used for green infrastructure, water or energy efficiency improvements, or other environmentally innovative activities. While the Iowa SRF has projects that can be to funded with the remaining 80 percent, there are currently few fundable proposals for “green” projects.

Eligible stormwater management projects might include:

Water efficiency
o Reclamation, recycling, and reuse of rainwater, condensate, degraded water, stormwater, and/or wastewater streams

Stormwater quality management
o Stormwater infrastructure with a treatment component
o Stormwater retrofits that address hydrologic impacts to receiving waters by reducing discharge flow volume
o Street sweepers and vacuum trucks

Green infrastructure
o Implementation of green streets (green infrastructure practices in transportation right-of-ways)
o Porous paving, bioretention, green roofs
o Establishment or restoration of riparian buffers
o Retrofits to keep stormwater out of sewer system

All of the projects funded through the stimulus funds must have an environmental review and must comply with all federal regulations

Caltha LLP provides expert technical support to clients nationwide in addressing environmental review, stormwater management and stormwater pollution prevention requirements.

[Read further information on Stormwater Plan - SWPPP Services]

[Read further information on Stormwater Training - SWPPP Training]

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Preventive Maintenance of Industrial Equipment - Permit Requirements

Maintenance of equipment and controls is a requirement for most stormwater pollution prevention programs. Maintenance can be 1) routine maintenance to correct deficiencies identified during routine inspections, and 2) preventive maintenance to address problems before they occur. In many jurisdictions, a written Preventive Maintenance Plan is required.

In most cases, two types of equipment or systems must be maintained:

1. Industrial equipment and systems, and
2. Stormwater BMPs and Stormwater Controls

Relative to industrial equipment and systems, routine maintenance and preventive maintenance is required for equipment and systems that could result in stormwater impacts if not properly maintained. Using the recent US EPA Multisector Permit (MSGP-2008) as one example, dischargers "must regularly inspect, test, maintain, and repair all industrial equipment and systems to avoid situations that may result in leaks, spills, and other releases of pollutants in stormwater discharged to receiving waters."

In addition, the MSGP-2008 requires that equipment that is awaiting maintenance be handled separately. Dischargers are required to "confine the storage of leaky or leak-prone vehicles and equipment awaiting maintenance to protected areas."

[Read more about maintenance requirements for stormwater controls and BMPs]

Caltha LLP provides expert technical support to clients nationwide in addressing stormwater permitting and SWPPP requirements, including developing effective inspection and preventive maintanence programs, and providing employee training programs.

[Read further information on Stormwater - SWPPP Services]

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Maintenance of Stormwater Controls - BMPs - Regulatory Requirements

Once installed stormwater Best Management Practices (BMPs) or stormwater controls need to be maintained in order to remain effective. The most intuitive example is a stormwater detention basin or pond. If the pond is sized to remove 90% of suspended solids, it will only meet this target removal efficiency if it is maintained at its designed size. Over time, an effective pond will trap sediment; this sediment displaces the water volume in the pond and its removal efficiency begins to drop. Without maintenance (which in this example would be removing accumulated sediment), the pond will eventually approach 0% removal efficiency.

From a regulatory perspective, most State permits require that stormwater BMPs be maintained; in this context, BMPs could be any structural or non-structural control measure that the site uses.

Using the recent US EPA Multisector General Permit (MSGP-2008) as an example, dischargers must "maintain all control measures ... in effective operating condition. Nonstructural control measures must also be diligently maintained (e.g., spill response supplies available, personnel appropriately trained). If you find that your control measures need to be replaced or repaired, you must make the necessary repairs or modifications as expeditiously as practicable."

Maintenance of stormwater controls requires:

• Scheduled routine inspections, conducted by qualified staff
• Detailed evaluation under comprehensive site compliance evaluations
• Detailed documentation
• Rapid corrective action

Industrial sectors that are required to conduct routine benchmark monitoring will find maintenance to be especially important. In addition to conducting routine visual inspections of their controls, they will also be collecting and analyzing samples of their stormwater discharge in order to demonstrate that their controls remain effective.

Caltha LLP provides expert technical support to clients nationwide in addressing stormwater permitting and SWPPP requirements, including developing effective inspection and preventive maintanence programs, and providing employee training programs.

[Read further information on Stormwater - SWPPP Services]

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Stormwater Infiltration - Regulatory and Permitting Aspects

Infiltration is used as a stormwater control or Best Management Practice (BMP) in many areas. However, infiltrating run-off has some unique regulatory issues. First, in some States, infiltrating stormwater is a viable means to eliminate a discharge that would otherwise require an NPDES discharge permit. However, in most cases, the system would need to infiltrate all run-off from even the largest rain events. In addition, seasonal changes must also be considered; all run-off would need be collected and infiltrated even during frozen conditions. Some States regulate groundwater as a "water of the State", and therefore can regulate discharges to the groundwater using infiltration.

Here are two recent examples:

New Hampshire. New Hampshire has recently proposed requiring a "Alteration of Terrain" permit for many types of new projects. Infiltration of stormwater is prohibited if the run-off comes from "high load areas", which include many typical industrial activities.

[Read more about New Hampshire Alteration of Terrain permits]

Minnesota. The Minnesota Pollution Control Agency (MPCA) has been drafting regulations relating to infiltration of stormwater at sites regulated under the industrial stormwater discharge general permit. These requirements are still in revision, however as of November 2008 the format for regulation of infiltration as a stormwater control has included:

• Design criteria for amount of run-off to be infiltrated


• Rate at which infiltration must occur after a storm event


• Pretreatment requirements for run-off prior to discharge to designed infiltration basin


• Stormwater monitoring requirements and standards ("benchmarks") for run-off prior to discharge to designed infiltration basin


• Operation and maintenance requirements.

The draft MPCA infiltration requirements also include several prohibitions, where infiltration can not be used to manage stormwater. These include:

• Certain industrial sectors are prohibited from using infiltration BMPs;


• Certain sensitive areas where groundwater is vulnerable to contamination, including karst areas, and well head protection areas.
  

Finally, under some circumstances the disposal of stormwater run-off using a designed infiltration system can be further regulated as a Class V Injection Well. This will require further permitting and associated regulation.

Caltha LLP provides expert technical support to clients nationwide in addressing stormwater permitting and SWPPP requirements.

[Read further information on Stormwater Plan - SWPPP Services]

[Read further information on Stormwater Training - SWPPP Training]

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

NH Alteration of Terrain Permit – High Load Areas

The New Hampshire Department of Environmental Services (DES) has recently finalized new rules requiring an Alteration of Terrain Permit (AOT) for many types of construction projects. The purpose of these rules to protect drinking water supplies, surface waters, and groundwater by specifying the procedures and criteria for obtaining permits required by the rule. These rules shall apply to any person proposing to:
(a) Dredge, excavate, place fill, mine, transport forest products, or undertake construction in or on the borders of surface waters; or
(b) Significantly alter the characteristics of the terrain in such a manner as to impede the natural runoff or create an unnatural runoff.

One key aspect of the rule is the definition and requirements for “High-Load Areas”. High-load areas include:
(1) Industrial facilities subject to the NPDES Multi-Sector General Permit;
(2) Petroleum storage facilities;
(3) Petroleum dispensing facilities;
(4) Vehicle fueling facilities;
(5) Vehicle service, maintenance and equipment cleaning facilities;
(6) Fleet storage areas;
(7) Public works storage areas;
(8) Road salt facilities;
(9) Commercial nurseries;
(10) Non-residential facilities having uncoated metal roofs with a slope flatter than 20%;
(11) Facilities with outdoor storage, loading, or unloading of hazardous substances, regardless of the primary use of the facility; and
(12) Facilities subject to chemical inventory under EPCRA Section 312.

A Source Control Plan may need to be prepared and submitted to NHDES for any proposed projects that include high-load areas and larger commercial parking areas.

The new rule also details requirements that apply to stormwater management practices from high-load areas, which include:

• Prohibition on groundwater recharge;
• Prohibition on infiltration practices;
• Prohibition on stormwater filtering practices, without an impermeable liner; and
• Prohibition on stormwater swale practices, without an impermeable liner.
  

Caltha LLP provides expert technical support to clients nationwide to develop cost effective pollution prevention programs to meet State and Federal requirements.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Polyaromatic Hydrocarbon (PAH) in Sealants - Stormwater Impact Studies

Collaborative studies by the City of Austin, TX, and the U. S. Geological Survey have identified coal-tar based sealcoat as a major and previously unrecognized source of polycyclic aromatic hydrocarbon (PAH) contamination. Several PAHs are suspected human carcinogens and are toxic to aquatic life.

Studies in Austin, Texas, showed that particles in runoff from coal-tar based sealcoated parking lots have concentrations of PAHs that are about 65 times higher than concentrations in particles washed off parking lots that have not been sealcoated. Biological studies, conducted by the City of Austin in the field and in the laboratory, indicate that PAH levels in sediment contaminated with abraded sealcoat are toxic to aquatic life and are degrading aquatic communities.

This research has led the City of Austin to ban the use of coal-tar sealants for roads, parking lots, driveways, and other paved areas.

Caltha LLP assists private and public sector clients in evaluating potential stormwater pollution sources and developing cost effective stormwater pollution prevention programs to minimize their environmental impacts.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Infiltration Basins - Draft Requirement for Retrofit of Existing Basins

UPDATE: On July 6, 2009, MPCA is scheduled to release its proposed Multisector Industrial General Stormwater Permit. In July, Caltha LLP will be hosting seminars in several cities across Minnesota to provide information on the proposed permit and rule changes, and steps facilities can take to reduce their impact.

For more information, go to:

MPCA SWPPP Permit - Industrial Stormwater Permit Reissue Seminars

++++++++++++++++++++++++++

On December 18, 2008, the Minnesota Pollution Control Agency released a redraft of the Multisector Industrial General Permit (MSGP) currently being written. This version of the permit provides some additional requirements on the design of infiltration basins. [Read more about the regulatory aspects of infiltration basins]


As discussed previously, MPCA has included specific design and monitoring requirements for infiltrations basins. These include several situations and industrial sectors for which infiltration basins are forbidden.

One on the key elements of the MPCA requirements for infiltration basins is the RETROFIT of existing infiltration basins which do not currently meet the new design criteria. Existing infiltrations basins must be upgraded to meet the new requirements within one year of promulgation of the MSGP.

The MPCA MSGP is a work in progress; revisions and additions to the permit continue to be made. Once a draft is completed, the permit will be issued for public comment. Because of the size and complexity of the draft permit (especially compared to the current permit, written in 1997), it is expected that there will be significant public comments.

Caltha LLP provides expert technical support to industrial facilities nationwide subject to stormwater permitting requirements.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Stormwater Effluent Limits On Construction Site Discharges

On November 28, 2008, US EPA published its proposed revision to the federal requirements on stormwater discharges from construction sites. The key departure in the current proposal from existing requirements is the establishment of New Source Performance Standards (NSPS) and numeric effluent limit guidelines (ELG) that will apply to construction sites.

[Read more about the difference between "effluent limit" and "stormwater benchmarks]

[Read more about typical concentrations in stormwater compared to limits]

In June 2008, US EPA published its final general stormwater discharge permit for construction sites. US EPA’s intent is to issue a revised general permit once these new effluent limits are promulgated.

The current proposed rule addresses controls based on size of the construction site:

1. Less than 10 acres. Controls are similar to current approaches.
2. Greater than 10 acres. Sites greater than 10 acres will need to install temporary sediment basins meeting specific design criteria.
3. Greater than 30 acres. For large sites, discharges will need to monitor stormwater discharges and must meet a turbidity effluent limit of 13 nephelometric turbidity units (NTU). The effluent limit of 13 NTU is based on the determination that the Best Available Technology (BAT) has been demonstrated to meet this limit. In this case, the BAT is active treatment on-site using injection of polymer into the stormwater to improve precipitation of smaller particles.
   

Does this mean that all large construction sites will need to install active stormwater treatment systems? Not necessarily. Large sites subject to the effluent limit of 13 NTU will need to meet that limit. Sediment basins alone may not be capable of meeting this limit, and if so active treatment, including enhanced precipitation using chemical addition, may be required.

Once the US EPA finalizes the effluent limits for large construction sites, State general permits will likely include these permit limits as they are reissued. US EPA is accepting comments on the proposed Rule through February 26, 2009.


Caltha LLP assists dischargers as they evaluate and address regulatory obligations under State and Federal stormwater permits.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

EPCRA 313 Facility Requirements Under Stormwater Discharge Permits

When initially drafted, the US EPA general discharge permit for industrial stormwater discharges contained additional requirements which applied to selected facilities that stored and used larger quantities of chemicals. These requirements applied to a subset of EPCRA (also referred to as SARA) Section 313 reporting facilities; because a facility was required to submit a Toxic Release Inventory (TRI) report did not necessarily mean that these additional requirements had to be met under their stormwater discharge permit. The additional requirements included:

• Specific containment/diversion requirements
• Additional inspections
• Material compatibility requirements
• Site security
  

Over time, as “sector specific” or “multi-sector” general permits became more common, the need for additional requirements for Section 313 facilities became less critical. These requirements could be inserted into the requirements for individual industrial sector that typically used Section 313 chemicals.

Currently, only about one-third of States have general industrial permits that include additional requirements for EPCRA 313 facilities.

Caltha LLP provides technical support to facilities nationwide to meet their State-specific stormwater permitting requirements. Caltha maintains a library of SWPPP templates, Monitoring Plan templates, and SPCC templates to meet individual State requirements.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

New North Carolina (NCDENR) Stormwater Rules for Discharges to Sensitive Water

New Division of Water Quality stormwater rules became effective October 1, 2008 in North Carolina for coastal areas which drain to shellfishing areas or other high value water resources. The new rules regulate new development and redevelopment projects. The major areas for change are 1) coverage (non-residential), 2) low density thresholds, 3) design storm requirements, 4) wetlands and impervious surface calculations, and 5) vegetative buffer size.

In areas within one-half mile of shelling fishing areas, percent impervious cover must be <12%>MS4 stormwater discharge permits as they are reissued.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Pennsylvania DEP PPC Plan Requirements Compared to SWPPPs

The general permit for industrial stormwater discharges in Pennsylvania requires dischargers to prepare and implement a “Preparedness, Prevention and Contingency (PPC) Plan. This plan is unique to Pennsylvania dischargers; however, other States and the US EPA refer to a Stormwater Pollution Prevention Plan (SWPPP) to fill the same planning function.

The PPC Plan is equivalent to a typical SWPPP in many respects. Both PPC Plans and SWPPP include:

• Stormwater Management Practices
• Erosion and Sedimentation Control Practices
• Control of Non Stormwater Discharges
• Site Inspections
• Stormwater Monitoring
• SWPPP Training
• Special Requirements Applicable to SARA 313 Facilities

However, the PPC Plan has some unique requirements that are not typically part of SWPPP compliance requirements. One of the key differences includes the specific requirements for stormwater controls to be included in the PPC:

• Specific Best Management Practices (BMPs) or stormwater controls need to be “considered” by all dischargers (e.g., “Consider installing spill and overfill prevention equipment”)
• Specific Best Management Practices (BMPs) or stormwater controls required for all dischargers (e.g., “Install oil/water separators or oil and grease traps in fueling area storm drains.”, “Do not dispose of oil filters in trash cans or dumpsters”)
• Specific Best Management Practices (BMPs) or stormwater controls required for individual industrial sectors (e.g., “use drip pans when loading or unloading liquids”, “eliminate the use of chlorine products”, “install and use dust control/collection systems”)

Contact Caltha LLP for more information on PPC templates for industrial sectors in Pennsylvania.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Using Infiltration as Stormwater BMP - Regulatory Issues

Infiltration is used as a stormwater control or Best Management Practice (BMP) in many areas. However, infiltrating run-off has some unique regulatory issues. First, in some States, infiltrating stormwater is a viable means to eliminate a discharge that would otherwise require an NPDES discharge permit. However, in most cases, the system would need to infiltrate all run-off from even the largest rain events. In addition, seasonal changes must also be considered; all run-off would need be collected and infiltrated even during frozen conditions. Some States, such as Minnesota, regulate groundwater as a "water of the State", and therefore can regulate discharges to the groundwater using infiltration.

The Minnesota Pollution Control Agency (MPCA) has been drafting regulations relating to infiltration of stormwater at sites regulated under the industrial stormwater discharge general permit. These requirements are still in revision, however as of November 2008 the format for regulation of infiltration as a stormwater control has included:

• Design criteria for amount of run-off to be infiltrated
• Rate at which infiltration must occur after a storm event
• Pretreatment requirements for run-off prior to discharge to designed infiltration basin
• Stormwater monitoring requirements and standards ("benchmarks") for run-off prior to discharge to designed infiltration basin
• Operation and maintenance requirements.

The draft MPCA infiltration requirements also include several prohibitions, where infiltration can not be used to manage stormwater. These include:

• Certain industrial sectors are prohibited from using infiltration BMPs;
• Certain sensitive areas where groundwater is vulnerable to contamination, including karst areas, and well head protection areas.

Finally, under some circumstances the disposal of stormwater run-off using a designed infiltration system can be further regulated as a Class V Injection Well. This will require further permitting and associated regulation.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

MPCA Industrial Stormwater - Key Elements of Draft Permit

UPDATE: On July 6, 2009, MPCA is scheduled to release its proposed Multisector Industrial General Stormwater Permit. In July, Caltha LLP will be hosting seminars in several cities across Minnesota to provide information on the proposed permit and rule changes, and steps facilities can take to reduce their impact.

For more information, go to:

MPCA SWPPP Permit - Industrial Stormwater Permit Reissue Seminars

++++++++++++++++++++++++++

The Minnesota Pollution Control Agency has been drafting its revised general permit for stormwater discharges from industrial sites. The current general permit was written in 1997, and the upcoming revision will reflect major changes in stormwater permitting requirements.

A partial draft permit was released on November 20, 2008. This draft did not contain some important sections of the permit – most significantly, it did not include any SECTOR SPECIFIC requirements which will be incorporated into the final permit. All sections of the draft are subject to further revision; this article provides a briefing on some of the key elements of the draft permit.

Some key requirements in the draft permit are:

Requirements for Designated “Special” Waters. MPCA intends to have additional requirements for stormwater discharges to a number of different types of special waters, such as trout streams, wetlands and others. The nature of these additional requirements has not been released.

Facility Inspections. Facility inspections will need to be conducted on a monthly basis. All employee(s) performing inspections must be trained.

Maintenance of BMPs. If BMPs/structural controls are found to be not functioning properly, repairs should be made within seven days. Anyone performing installation, inspection, maintenance and repair of BMPs must have appropriate training.

Mercury Minimization Plan. Each permittee must evaluate their facility to determine if any sources of mercury are potentially exposed to stormwater. If mercury sources or devices are found, a Mercury Minimization Plan must be developed.

Stormwater Monitoring. The most important change compared to the current MPCA general permit is the requirement to sample stormwater discharges. All permittees will collect and analyze at least four quarterly samples during Year 2 of permit coverage. Depending on the results, further samples may need to be collected in Year 4 and 5, and corrective actions may be required. Additional reporting and evaluations will be required for dischargers who continue to exceed benchmark concentrations.

Related Links:
Flowchart of Draft MPCA Stormwater Monitoring Requirements
Further information on stormwater benchmarks
Comparison of stormwater benchmarks to typical discharge data
Further information on selecting stormwater monitoring techniques

Special Requirements for Stormwater Infiltration. MPCA intends to include specific requirements for the design and operation of infiltration BMPs. For some industry sectors, infiltration will be prohibited.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Local Stormwater Requirements - Additional Stormwater Compliance Requirements

One of the challenges many facilities face is complying with local stormwater requirements. These requirements are beyond those requirements specified in an NPDES permit. In fact, many local requirements apply to all properties, regardless of SIC code or whether or not a facility is required to obtain a discharge permit.

One of the most challenging aspects of complying with local requirements is the fact that different jurisdictions can have widely different requirements. Cities, Counties or other jurisdictions can range from very generic requirements, or very detailed requirements. For example, the City of Tampa Bay, Florida has general requirements:

Sec. 21-9. Protection of public drainage systems. •It is unlawful to introduce any foreign matter (including, but not limited to, trash, leaves, grass clippings, debris, garbage, fill, construction materials, organic or inorganic pollutants, acids, and petroleum products), whether by action or inaction, to any public drainage system including but not limited to streets.

In contrast, the City of Fremont, CA, for example, has very prescriptive requirements. Here is a small sample of the City's requirements:

I.K. Vehicle/Equipment Repair and Maintenance –1) Vehicle/equipment repair and maintenance shall be performed in a designated area indoors, or if such services must be performed outdoors, in an area designed to prevent the run-on and runoff of stormwater. 2) Secondary containment shall be provided for exterior work areas where motor oil, brake fluid, gasoline, diesel fuel, radiator fluid, acid-containing batteries or other hazardous materials or hazardous wastes are used or stored. Drains shall not be installed within the secondary containment areas.

Whether the local requirements are general or specific, in most cases, NPDES permits require compliance with local requirements in addition to permit conditions. In preparing SWPPPs, local requirements need to be considered in addition to the permit requirements.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website

Polycyclic Aromatic Hydrocarbons in Stormwater - Austin Sealcoating Studies

Collaborative studies (Fact Sheet) by the City of Austin, TX, and the U. S. Geological Survey have identified coal-tar based sealcoat as a major and previously unrecognized source of polycyclic aromatic hydrocarbon (PAH) contamination. Several PAHs are suspected human carcinogens and are toxic to aquatic life. Studies in Austin, Texas, showed that particles in runoff from coal-tar based sealcoated parking lots have concentrations of PAHs that are about 65 times higher than concentrations in particles washed off parking lots that have not been sealcoated. Biological studies, conducted by the City of Austin in the field and in the laboratory, indicate that PAH levels in sediment contaminated with abraded sealcoat are toxic to aquatic life and are degrading aquatic communities, as indicated by loss of species and decreased numbers of organisms.

This research has led the City of Austin to ban the use of coal-tar sealants for roads, parking lots, driveways, and other paved areas.

For further information contact Caltha LLP at
info@calthacompany.com
or
Caltha LLP Website