Tag: Stormwater Engineering

The New Hampshire MS4 Stormwater Permit: What’s Next?

Image of a stormwater outfall area as body of water

For our friends in the MS4 communities, hopefully, you completed the Year 1 requirements to meet the June 30, 2019 deadline. This included, among other things, completion of a Stormwater Management Plan (SWMP), Illicit Discharge and Detection Elimination (IDDE) Plan, outfall ranking and prioritization for subsequent outfall investigations, construction site runoff control procedures, a schedule for catch basin cleaning, a schedule for street sweeping, written winter road maintenance procedures, distribute two targeted messages (depending on the community), and develop a Chloride Reduction Plan. So, what’s next?

MS4 communities must continue to work on/update the stormwater system mapping. This includes key elements and features of the stormwater conveyance system, structural Best Management Practices (BMPs), open channels, etc. 2003 MS4 communities have two years (until June 30, 2020) to complete the update of the stormwater system mapping. New MS4 communities as of the 2017 MS4 have 3 years (until June 30, 2021) in which to complete the mapping of their stormwater system. As part of this effort, the initial catchment delineations should be refined as well. Systematic investigation of problem catchments, or high-priority catchments if there are no problem catchments, is to be started. A written catchment investigation procedure must be developed by December 31, 2019.

The investigation of problem and high-priority outfalls starts with a field inspection during dry weather. If dry-weather flow is observed, then further screening is required to determine if there may potentially be illicit discharges present. This can be done using field test kits; however, screening for bacteria requires laboratory testing. The results of the screening will determine whether additional investigation is required to determine sources of illicit discharges. The outfall ranking and prioritization will also be updated accordingly.

Stormwater outfall concrete pipe with water draining out of itGood housekeeping procedures must be developed for permittee-owned facilities, including: develop inventory of all permittee-owned facilities; develop O&M procedures for municipal activities; develop O&M procedures to reduce/minimize/eliminate discharge of pollutants; develop and implement Stormwater Pollution Prevention Plan (SWPPP) for municipally-owned facilities such as maintenance garages, public works yards, salt sheds, transfer stations and other areas where pollutants are exposed to stormwater; and cover salt storage areas. Are you having fun yet?

Public Education and Outreach activities must be continued during Year 2. This involves distributing two targeted messages.

Permittees lucky enough to have discharges to waters with an approved Total Maximum Daily Load (TMDL) have additional activities to complete during Year 2 as well. Permittees subject to an approved TMDL for chlorides must begin implementation of their Chloride Reduction Plan. Permittees subject to an approved bacteria and pathogen TMDL must disseminate public education materials and work on implementation of their IDDE plan. Permittees subject to a phosphorus TMDL must have a legal analysis of their Lake Phosphorus Control Plan (LPCP) completed.

Permittees with discharges to impaired waters without an approved TMDL would be well advised to begin planning for future MS4 permit obligations as well. Impairments to waters without an approved TMDL include: nitrogen, phosphorus, bacteria or pathogens, chloride, total suspended solids, metals, and oil and grease. Did you know that leaf litter contributes phosphorus and nitrogen to stormwater runoff?

Did I mention that the Year 1 annual report must be completed and submitted by the EPA-extended date of September 30, 2019? The reporting period for Year 1 is from May 1, 2018 to June 30, 2019. The reporting period is from July 1 to June 30 for all subsequent years. The EPA has developed a template based on the 2017 MS4 permit that can be used for the annual report. The template can be found here.

The Hoyle, Tanner team of experts is available to assist you as needed with MS4 permit compliance. If you have questions, please contact Michael Trainque (mtrainque@hoyletanner.com) or Heidi Marshall (hmarshall@hoyletanner.com) at Hoyle, Tanner & Associates, Inc.

 

Additional information:

https://www.epa.gov/npdes-permits/new-hampshire-small-ms4-general-permit

https://www.epa.gov/npdes-permits/stormwater-tools-new-england#arr

MS4 Regulations in New Hampshire Communities: How to Deal with Stormwater

Storm Drain Photo

Whew!! You got that Notice of Intent form submitted (hopefully) to EPA on or before October 1. Now what? Grab a cold one, sit back, relax? Wishful thinking. Now the real fun begins.

Stormwater Sampling For those communities that have not already done so, stormwater outfalls from the MS4 area must be located, mapped and assigned a unique identification number. Then an inspection and condition assessment must be done for each outfall. If you were an MS4 community subject to the 2003 permit, you would have (or at least should have) completed this. However, you are not finished. Mapping completed pursuant to the 2003 MS4 permit must be updated with significantly more detail added per the 2017 MS4 permit. You have 2 years to complete the update. If you are a new MS4 community subject to the 2017 MS4 permit, you need to start this process and complete it within 3 years. For all MS4s, the stormwater mapping must be updated annually; and catch basins, catchment areas, manholes, and other features must be added. You must also complete an outfall inventory and ranking. The ranking is based on potential for illicit discharges and sanitary sewer overflows. Are we having fun yet??

If flow is observed from any outfalls during dry weather, it will be necessary to conduct dry-weather sampling and testing of each outfall in which dry-weather flow was observed in order to determine if there are potentially illicit discharges in the outfall. Outfalls must be ranked as “Problem”, “High-Priority”, “Low-Priority”, or “Excluded” based on known or suspected illicit discharges or sewer system overflows. This is all part of the required Illicit Discharge Detection and Elimination Program (IDDE). Did I mention you need to complete a written IDDE program within one year (by June 30, 2019)?

A number of New Hampshire communities are specifically listed in the 2017 MS4 permit based on discharges to waters with an approved Total Maximum Daily Load (TMDL) and/or based on discharges to certain water quality limited (impaired) waters without an approved TMDL. Approved TMDLs include chlorides, bacteria or pathogens, and phosphorus.

How is your Phosphorus Reduction Plan coming along?
Impairments to waters without an approved TMDL include: nitrogen, phosphorus, bacteria or pathogens, chloride, total suspended solids, metals, and oil and grease. Did you know that leaf litter contributes phosphorus and nitrogen to stormwater runoff?

How is your Chloride Reduction Plan coming along?
The written Plan has to be completed within 1 year (on or before June 30, 2019). There are also specific requirements for public education and outreach as well as public participation including messages and outreach to target audiences.

How are your stormwater regulations?
MS4 communities need to update their stormwater regulations and ordinances (if you already have them) or develop and implement regulations for managing stormwater (if you do not have them).

By the way, did I mention that all of the foregoing has to be addressed in your Stormwater Management Plan? The Hoyle, Tanner team of experts is available to assist you as needed with MS4 permit compliance. If you have questions, please contact me or Heidi Marshall for assistance.

5 Facts About Sustainable Stormwater Practices

*Note that this post was originally published in 2014 and has been updated in 2020.

In urban and densely populated suburban areas where the highest concentration of impervious surfaces are found, stormwater runoff can be a significant contributor to water pollution. As rain falls in outlying rural areas, the water is absorbed and filtered by the natural vegetation and soil. The impervious surfaces, including roofs, sidewalks, paved parking areas and wide city streets, do not allow the ground to absorb the water and instead is collected in closed drainage systems and often time discharged into nearby surface waters without filtration.

Here we review 5 Facts About Sustainable Stormwater Practices to help communities and agencies that may be planning to develop new “green” infrastructure.

  1. Regulatory Compliance: Stormwater is regulated at the federal level by the Environmental Protection Agency (EPA) under the Clean Water Act (CWA). The CWA “establishes the basic structure for regulating discharges of pollutants into the waters of the United States and regulating quality standards for surface waters.” Thus making it “unlawful to discharge any pollutant from a point source into navigable waters, unless a permit was obtained.” State Environmental Agencies often apply additional requirements beyond EPA minimum standards to further protect impaired state waters. On a local level, some communities have developed Stormwater Management Plans to assist managing discharge from both private and public properties. Local Ordinances are crafted by community officials as an integral part of subdivision and site plan development review and approval processes. New stormwater regulations often require implementation of sustainable stormwater management practices.
  2. Green Materials: “Green” or sustainable stormwater best management practices treat stormwater as a resource to be preserved and maintained, taking advantage of natural processes to clean and filter stormwater runoff.  Vegetation and soil filtration highlight the obvious green materials used, but some methods growing in popularity include permeable pavement, down spout disconnection, rainwater harvesting, rain gardens, planter boxes, tree filters, green roofs, bioswales, as well as land conservation. With the incorporation of one or more of these design features, urban spaces are able to reduce the percentage of impervious surfaces thus reducing the volume of stormwater runoff.
  3. Public-Private Partnerships: State and local governments collaborating with developers on properties within different regions to incorporate Green Infrastructure into the design/redesign will in turn save money via stormwater diversion and treatment by the agencies. Offering tax credits or incentives to the developers is intended to accelerate the adoption of these improved stormwater management practices leading to more extensive implementation statewide.
  4. Funding Availability: Many funding options are available through federal and state agencies including EPA, Departments of Transportation, US Economic Development Administration (EDA), Department of Housing and Urban Development (HUD), National Oceanic and Atmospheric Administration (NOAA), as well as the Departments of Agriculture, Energy and Treasury. Grants available through these agencies will help offset the cost for municipal and private entities to invest in sustainable stormwater collection, filtration and treatment upgrades to existing or redeveloping sites.
  5. Benefits: Environmental – Improperly managing stormwater runoff into surface waters can contain pollutants from the surfaces it is diverted from, potentially causing damage to aquatic vegetation and wildlife. Uncontrolled stormwater runoff can also cause physical damage such as erosion and flooding.  With the implementation of green infrastructure practices, contaminants can be reduced in the receiving water bodies and create healthier environments. Social – Incorporating sustainable stormwater management practices can improve water quality, quantity and aesthetics, thereby enhancing the livability of a community, creating multifunctional landscapes and green spaces, encouraging revitalization, and providing educational opportunities. Economic – The use of green infrastructure may provide incentives to attract investment; reinvigorate neighborhoods; inspire redevelopment; or provide new recreational opportunities.

To find out more about community stormwater management practices, the EPA has issued resources outlining practices to assist while achieving other environmental, social and economic benefits.