The Maine Stormwater Law
and Rules: Some Basic
ConceptsMarybeth Richardson
Director, Southern Maine Regional Office
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTIONProtecting Maine’s Air, Land and Water
Chapter 500 – A Brief History
• 1995 – Maine Storm Water Management Law
• 1997 – Chapter 500 Stormwater Management Law Rules
• 2006 ‐ Stormwater Management Rules last updated
• 2009 – Stakeholder group discussions
• 2015 – Major revisions
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
Chapter 500 – 2015 Revisions• New changes effective 8/12/2015
• General standards – options when 95% and 80% treatment levels can’t be met
• Redevelopment standards
• Innovative treatment measures
• Clarification of treatment standards for Site law redevelopment projects
• Rainfall table updates
• Voluntary low impact development credit
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
Redevelopment
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
• Treatment requirement based on the pollutant discharge that would occur if stormwater went untreated
• Pollutant ranking based on Table 2 – land uses• Calculate treatment level based on existing
land use vs. proposed condition• Priority for treatment given to areas with
highest pollutant ranking to maximum extent practicable
• Developed area must be treated to the level required based on pollutant ranking in Table 3
• Department may allow equivalent treatment or mitigation on an off‐site parcel as alternative if treatment of developed area is impractical
Recertification Requirement
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
• Submit documentation within 3 months of every 5‐year interval from date of permit issuance
• Inspection of BMPs• Maintenance log for erosion
control• Proprietary systems – evidence
of maintenance• DEP may waive if MSGP or
MEPDES program requirements can be substituted
New Rule: Chapter 501• Allows for payment of
compensation fees or mitigation through reduction of existing pollutant sources
• Compensation fees only in towns with a “CFUP”
• Mitigation projects can be on‐site or off‐site
• Effective date 1/13/2015
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
Maine Construction General Permit • Introduced in 2003• Licenses discharges only from construction activities
• Expired in 2008, but coverage continues
• Threshold activities similar to Stormwater Permit‐by‐Rule
• Applicants who are applying for stormwater or Site Law permits are automatically covered
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
MCGP Proposed Changes• Definition changes
• Construction in Long Creek watershed
• Emergency‐related construction activities
• Non‐stormwater discharges
• Changes reviewed with EPA
• Draft currently under review
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
• Increase erosion control where a 50‐foot buffer to surface water cannot be maintained.
• Install sediment barriers downgradient of, and divert runoff to, soil stockpiles.
• Minimize tracking of sediment off the site.• Adequately protect storm drain inlets.• Design sediment basins to provide storage for a 2‐year, 24‐hour storm and remove sediment to maintain at least half the design capacity of the basin.
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
MCGP: Other potential changes
LID: Low-Impact DevelopmentSite planning and designstrategies intended to replace or replicate predevelopment hydrology through the use of source control and relatively small‐scale measures integrated throughout a site to disconnect impervious surfaces and enhance filtration, treatment, and management of stormwater runoff as close to its source as possible.
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
LID continued…• Encourages innovation
and creativity• Voluntary LID credit• Can be structural or
non‐structural• LID strategies should
be agreed upon by DEP early in review process
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
Stormwater and Climate ChangeDEP Adaptation Toolkit:• Centralized source of information for many stakeholders
• Developed with other state agencies
• Will continue to be updated over time
http://www.maine.gov/dep/sustainability/climate/adaptation-toolkit/index.html
MAINE DEPARTMENT OF ENVIRONMENTAL PROTECTION www.maine.gov/dep
Contact:Land Bureau Licensing Unit
Southern Maine Regional Office207.822.6300
www.maine.gov/dep