Green Infrastructure Solutions for MS4 Communities

Presentation led by David Braswell and Trey Wingate
GAZA Summer Conference August 2014
Augusta, GA

Green Infrastructure Defined

  • Sustainable watershed and stormwater management solutions that use soil and vegetation to consider all sources of pollution in a watershed; maintain and restore the natural hydrologic cycle; and advance community health, safety, and quality of life objectives.

Green Infrastructure Challenges

  • Despite benefits, Green Infrastructure (GI) approaches remain elusive in many communities
  • Successful GI solutions require the integration of professional skills, from planning to design to construction to O&M
  • Communities often have some portions of the needed tools to implement GI solutions, but lack others
  • Appropriate skills may be scattered among various departments

How do we get there from here?

  • Communities have taken many different approaches
  • Much of the work done to date has been the result of EPA CSO/SSO Consent Decrees
  • GI/LID techniques in early stages of development; benefits of BMPs may vary widely from place to place
  • Monitoring results from in-place BMPs are only now beginning to show results

US EPA Direction

  • – In 2012, EPA issued 6 fact sheets and 2 supplements on GI implementation
  1. General Accountability Considerations
  2. Combined Sewer Overflows (CSO)
  3. Sanitary Sewer Overflows (SSO)
  4. Stormwater
  5. Total Maximum Daily Load (TMDL)
  6. Water Quality Standards

Important Themes

  • Both Green and traditional (Gray) practices will likely be required in most urban areas
  • Define standards as desired result and use combinations of Green and Gray to achieve
  • May need interim as well as medium- and long-term targets (quantitative)
  • Monitoring is essential for both construction and O&M
  • Allow for uncertainty (Adaptive Management)


  • GI measures may be:
  1. Integrated into CSO LTCPs
  2. Ideal solutions for SSO inflow problems and may reduce capacity requirements
  3. Integrated into MS4 permits (specifying water volumes to be controlled on-site)
  4. Used to reduce the amount of TMDL allocated to future growth
  5. Effective tools to help meet Water Quality Standards (antidegradation)

How do I integrate GI measures into my Stormwater Management Program?

  • Minimum control measures required by MS4 permits can include GI components:
  1. Public education and outreach on stormwater impacts
  2. Public involvement / participation
  3. Illicit discharge detection and elimination
  4. Construction site stormwater runoff control
  5. Post-construction stormwater management in new development and redevelopment
  6. Pollution prevention / good housekeeping for municipal operations

Latest EPD Phase 1 MS4 permit

  • Contains GI / LID section
  • Ordinance review: revise codes, ordinances, other regs so that they do not prohibit the use of GI / LID practices. At a minimum, must address residential and commercial development, road design, & parking.
  • Techniques and structures: must have a program in place to consider GI / LID techniques and developing an inventory of structures – better site planning techniques; better site design techniques; low impact development structures

Latest EPD Phase 1 MS4 permit

  • Minimum GI / LID requirements
  • Legal Authority: revise codes, ordinances, other regs so they do not prohibit the use of GI / LID practices
  • GI / LID program: describe GI / LID techniques to be implemented and procedures for evaluating the feasibility of GI / LID techniques
  • GI / LID structure inventory: develop an inventory of privately owned non-residential and publicly-owne structures. Track newly-added structures.
  • Inspection Program: inspect all inventoried structures within 5 years; maintain publicly-owned structures and ensure that privately-owned NR structures are maintained

Common Issues among GI programs

  • Planning
  • Funding and Economics
  • Community Involvement
  • Hydrology and Hydraulics Studies
  • Ecological studies
  • Development / Ranking of Alternatives
  • Infrastructure Design
  • Maintenance

Planning (MCM #5)

  • Most efficient way to incorporate GI solutions is to integrate concepts early in the development process
  1. Community master planning
  2. Ordinances and standards
  3. Comprehensive park planning
  4. Planning for individual developments

Planning (MCM #5)

  • Often GI / LID techniques violate existing planning or development policies / regulations
  • Process may require changes in ordinances / codes that require legislative approval
  • Many different local government departments may be involved, as well as stakeholders.

Funding and Economics

  • For new development, GI / LID implementation can be required by local governments
  • Many of the larger GI programs across the country are being implemented because of EPA consent decrees
  • Major expenditures, from hundreds of millions to billions of dollars (EPA in 2012 compared 12 cities with GI programs ranging from $3 million to $2.4 billion.
  • GI program costs often compare favorably to Gray solutions and may be better received by communities

Funding and Economics

  • Size of the potential investments requires financial planning and potentially rate increases or new revenue sources
  • Virtually every situation is different; custom solutions need to be tailored to accomplish GI goals
  • Choices will not be easy in the current economic climate and will demand prioritization of efforts

Community Involvement

  • Taxpayers / ratepayers will ultimately bear the burden of most GI initiatives
  • Both Green and Gray infrastructure improvements can affect residents’ daily lives
  • Essential to involve stakeholders and the public and get buy-in to accomplish GI objectives
  • Enhances MCM #1


  • Green Infrastructure projects can often be valued community amenities
  • Can garner community support for water quality programs
  • Provide climatic, aesthetic, and recreational benefits as well as reducing non-point effects
  • Have been powerful catalysts for redevelopment
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