new development and significant development 12/21/20151 new development & significant...

New Development and Significant Development

04/21/23 1

New Development & Significant Redevelopment


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Phase II Minimum Control Measure

Post-Construction Stormwater Management in New Development and Redevelopment

•Develop a program, using an ordinance or other regulatory means, to address runoff from new development and redevelopment projects that disturb > 1 acre

•Implement strategies with a combination of structural and/or non-structural BMPs

•Ensure adequate long-term operation & maintenance (O&M) of BMPs


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Phase II Minimum Control Measure:

The BMPs chosen should:

be appropriate for the local communityminimize water quality impactsattempt to maintain pre-development runoff

conditions

• Participate in watershed planning efforts• Assess existing ordinances, policies, and

programs that address stormwater runoff quality• Provide opportunities for public participation

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EPA Resources

• Low Impact Development http://www.epa.gov/owow/nps/lid/

• Smart Growth http://www.epa.gov/smartgrowth/ Using Smart Growth Techniques as Stormwater Best

Management Practices Stormwater Guidelines for Green, Dense Redevelopment. Protecting Water Resources with Smart Growth

• National Management Measures to Control Nonpoint Source Pollution from Urban Areas http://www.epa.gov/owow/nps/urbanmm/index.html

• Post Construction Guidance Manual coming Fall 2007


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Auditing/Inspecting a New Development Program

• Specific new development requirements can vary significantly within the state

• How does the MS4 apply the new development standards in the MS4 permit?

• Does the MS4 have a stormwater manual?

• Base your audit/inspection primarily on enforceable conditions in the permit

• If permit is not specific, determine if the MS4’s new development program addresses the following components.


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Common Program Components

• Legal Authority• Stormwater Design Standards• Plan Review and Approval• Construction Inspection of New Development

Controls• Maintenance/Enforcement• Tracking and Monitoring• Training and Education


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Legal Authority

• Does the MS4 have the legal authority (ordinance) to: Require stormwater considerations during new

development and redevelopment planning Specify contents of plans Establish standards for BMPs performance Inspect BMPs during and after construction Require compliance with the approved plans Require maintenance of the BMP for the life of the

structure• What exemptions does the legal authority allow?


State Water Board Order WQ 2000-11

• Precedential decision on Standard Urban Storm Water Mitigation Plans (Development Standards)

• Development standards require treatment controls for new and significant redevelopment projects

• Regional Board MS4 permits must be consistent with the State Board’s decision


Provisions applicable to all categories

• Peak storm water runoff discharge rate• Conserve natural areas• Minimize storm water pollutants of concern• Protect slopes and channels• Provide storm drain system stenciling and

signage• Properly design outdoor material storage areas


Provisions applicable to all categories

• Properly design trash storage areas

• Provide proof of ongoing BMP maintenance

• Design standards for structural or treatment control BMPsVolume or flow based standard


SUSMP Numerical Design Standards

• Design standards for volumetric treatment control BMPs:85th percentile 24-hour rainfall eventVolume of runoff to achieve 80% volume treatmetn0.75 inch storm event

• Design standards for flow based treatment control BMPs:0.2 inches/hour intensityTwo times the 85th percentile hourly rainfall intensity


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Stormwater Design Standards

• Does the MS4 have clear, specific Stormwater Design Standards? Do the standards: Set minimally acceptable BMPs and sizing criteria? Address source controls as well as treatment controls? Address BMPs for different pollutants? Provide incentives (credits) for innovative practices

(like reduced impervious surfaces, buffers, etc.) Allow exemptions?

• What are the minimum thresholds for when the standards apply?

• Does the MS4’s ordinance require compliance with the stormwater design standards?


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Local Stormwater Manuals

• The Center for Watershed Protection’s Stormwater Manager’s Resource Center summarizes the basic requirements in a local stormwater design manual

• http://www.stormwatercenter.net/


Example: City of Los Angeles-BMP Manualhttp://www.lastormwater.org/WPD/download/partb.htm


Select the most efficient BMP for the pollutant(s) generated


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Plan Review and Approval

• How does the MS4 review and approve stormwater plans for new development and redevelopment?

How early in the planning process is stormwater addressed (e.g., conceptual planning stage?)

Is the review based on the MS4’s Stormwater Design Standards?

Does the MS4 document the process for plan review and approval (e.g., use a checklist)?

Are requirements for long-term O&M addressed during review?


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Plan Review and Approval – File Review

Conduct a review of the following types of files:

• Approved plan(s) for a private project with post-construction controls and one for a public project Do approved plans follow MS4 standards? Are they

detailed? Did the MS4 provide detailed comments to the developer?

• Approved maintenance agreement(s) Do the maintenance agreements discuss maintenance

responsibilities, inspection requirements, when maintenance may be needed, etc.?

• Inspection/enforcement file(s) for completed projects with post-construction controls How detailed are inspection reports? What type of

enforcement actions are taken?


Example: Stormwater Requirements Applicability Checklist http://www.sandiego.gov/development-services/news /pdf/ds-5601stormwtr.pdf


Example: Design Checklist


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Construction Inspection of New Development Controls

• Do construction inspectors verify that “post-construction” BMPs have been installed?

• Are inspectors trained on post-construction BMP design and installation?

• Are as-built plans developed?

• How is this information transferred to maintenance inspection staff?


New Development Example

• Santa Monica, CA

• City sends out a form to all owners of structural stormwater controls each year asking if the control had been inspected and maintained

• Owners who do not respond are prioritized for inspection by the City


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Maintenance

• How often does the MS4 inspect post-construction BMPs? BMPs on private

property; BMPs on public land?

• How does the MS4 ensure maintenance on private property? (maintenance agreements, MOUs, etc)

• Who maintains post-construction BMPs? MS4, private landowner, combination?


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Enforcement

• What type of enforcement options does the MS4 have to ensure post-construction BMPs are installed and maintained?

• Does the MS4 have an escalating enforcement plan to document steps that will be taken to address non-compliance

• Are staff educated on how to use penalty provisions when necessary?

• How often are the enforcement options used?


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Tracking and Monitoring

• How does the MS4 track the installation and maintenance of post-construction BMPs?

• Do they collect information on BMP types, locations, owners, maintenance schedules, inspection findings, etc.?

• How does the MS4 assess the effectiveness of post-construction BMPs?

Is this information sent back to plan review and inspection staff?


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Example: BMP Effectiveness Protocols

• Technology Acceptance Reciprocity Partnership (TARP) – CA, MA, MD, NJ, PA, VA

http://www.dep.state.pa.us/dep/deputate/pollprev/ techservices/tarp/

A uniform method to collect and evaluate data on technology performance and cost

• Washington’s Technology Assessment Protocol (TAPE)

http://www.ecy.wa.gov/programs/wq/stormwater/newtech/ tape_ctape.html

Intended for ultra-urban treatment technologies and those treatment technologies that do not have a chemical component for treatment


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Training and Education

• What type of training on new development does the MS4 provide to:

Plan review staff

Construction inspectors

BMP maintenance inspectors

Code enforcement, others?

• Does the MS4 also educate local developers and engineers so they develop adequate plans?

• Does the MS4 educate property owners on maintenance of BMPs?


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In-Field Activities

• Inspect post-construction BMPs to determine whether they are still installed and maintained

Use final, approved plans for the project

Assess whether both structural and source control BMPs were installed

Were any BMPs removed or modified?

Are the BMPs being maintained?


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Common Compliance Problems

• MS4 lacks specific standards for post-construction controls

• MS4 lacks review criteria, checklists, or a formal plan review process

• MS4 does not require maintenance of post-construction BMPs

• MS4 does not have a system to track structural and source control BMPs for inspections and on-going maintenance

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