Salmon Falls River (2005)

Maine Stormwater Best Management Practices Manual

On this page you will find:

Maine's Stormwater Best Management Practices Manual
Proprietary Systems
Five-year Recertification for Long-term Maintenance of Stormwater Management Systems
Engineering List Serve

Maine Stormwater Best Practices Manual

The Maine DEP recognizes the importance of managing stormwater to preserve the State’s natural resources. This manual was developed to assist communities, watershed groups, individuals, engineers, and developers in understanding stormwater impacts and to select appropriate Best Management Practices (BMPs) to manage stormwater from development, in accordance with the Maine DEP’s Chapter 500 Stormwater Management Rules.

Please note that the files below are in PDF format, unless otherwise indicated, and may take some time to load. To view PDF files, get Adobe Acrobat Reader.

The Stormwater BMP Manual has three volumes:

Volume I. Stormwater Management Manual This volume provides general information on the impacts of development, lists the DEP’s stormwater management objectives, and offers guidance to control stormwater runoff and associated pollutants.

Volume II. Phosphorus Control in Lake Watersheds: A Technical Guide to Evaluating New Development This volume outlines Maine’s phosphorus standards, which limit the amount of phosphorus that developments can add to a lake. It also outlines methods for reducing phosphorus loadings to meet the established standards. The following links provide additional information to Volume II of the Stormwater BMP Manual:

Volume III. BMP Technical Design Manual This volume provides technical information to assist in the selection and design of BMPs to control stormwater runoff and its impacts. Links to individual chapters from Volume III of the Stormwater BMP Manual follow:

For general questions on the Stormwater BMP Manual, contact: Jeff Dennis, (207) 215-6376. For specific technical or engineering/design questions, contact one of our environmental engineers in the region where your project is located:

  • Northern and Eastern Maine Region: Ken Libbey (207) 299-4823
  • Central Maine Region: Kerem Gungor (207) 446-3915
  • Southern Maine Region: Ben Viola (207) 822-6365

Proprietary Systems (Appendix B)

A system or practice designed for stormwater runoff treatment from a development has to meet all the stormwater requirements of Maine’s Stormwater Law, and the Chapter 500 Stormwater Management Rule to be considered equivalent to any of the suggested structures found in the BMP Manual. A proprietary system must be live-tested for a variety of storm lengths and intensities. The system must remove at least 60% total phosphorus, with at least similar removals metals (zinc and copper), and hydrocarbons; it must provide temperature reduction and channel protection storage detention either independently or in combination with another measure; and it must also be maintainable.

Filtration systems that store and treat a volume of water must be sized to store and treat 1.0 inch of runoff from the contributing impervious area and 0.4 inches of runoff from contributing landscaped areas.  If channel protection storage and cooling are required, they must be provided independently, and the stored volume must be released slowly over a 24 to 48-hour period and cooled.  Flow-through or hybrid systems that do not store the water quality volume prior to treatment must be sized so that they treat the entire volume of the 0.95-inch Type III 24-hour storm without bypass. Sizing of proposed systems that do not fit these two categories will be determined on a case-by-case basis with the goal of providing treatment for at least 90% of the annual runoff volume.

The DEP has reviewed the design and performance data from these following proprietary structures and can approve them as an alternative, or as an integral part of the treatment train for stormwater management. Each approval letter identifies the specific design for sizing, layout, installation and maintenance requirements that are necessary for the system to perform as approved.  The approval date of a letter will supersede any older version of the same approval.

The DEP reviews requests for new proprietary systems as they are received.  For additional information on this process, please contact David Waddell (207) 215-6932 or Jeff Dennis (207) 215-6376.

Five-year Recertification for Long-Term Maintenance of Stormwater Management Systems

Proper operation and maintenance of stormwater systems helps ensure that the BMP will continue to remove pollutants effectively over the long-term, decreasing the risk of re-suspending sediment, and therefore protecting water quality.  Appendix B.3 of the DEP’s Chapter 500 Stormwater Rules requires that a certification be sent to the DEP every five years stating that the stormwater management system was inspected, maintained, and repaired (if needed).  Following are some forms related to the 5-year recertification:

For questions regarding the 5-year recertification process, please contact one of our environmental engineers in the region where your project is located:

  • Northern and Eastern Maine Region: Ken Libbey (207) 299-4823
  • Central Maine Region: Kerem Gungor (207) 446-3915
  • Southern Maine Region: Ben Viola (207) 822-6365

DEP Stormwater Engineering List serve

The DEP maintains a list for persons interested in DEP Stormwater topics. Periodically, the DEP sends out updates on revisions to the stormwater law or rule, changes to the Stormwater BMP Manual, or other topics of interest. You are invited to sign up with the DEP stormwater engineering list serve to receive these updates.

Sign up to be on the list serve.

If you have any questions on the list serve, please contact Kerem Gungor (207) 446-3915.