Transcript Slide 1

Operation & Maintenance
of Permanent Stormwater
Controls
Overview of Inspection Requirements
Laura Prickett, AICP, CPESC
EOA, Inc.
Construction Inspection Workshop
April 11, 2013
Outline of Presentation
 Permanent Stormwater Controls that
Require O&M Verification Inspections
 O&M Requirements in the Municipal
Regional Stormwater Permit
 The O&M Verification Inspection Plan
 Tools for Conducting, Tracking and
Reporting O&M Inspections
 For more information…
Permanent Facilities that
Require O&M Inspections
 Provision C.3.h of the MRP requires
agencies to conduct inspections to verify
operation & maintenance (O&M) of:
• Stormwater treatment measures, and
• Hydromodification management measures
Stormwater Treatment
Measures
 Engineered systems that remove
pollutants from stormwater runoff
Bioretention Area (biotreatment)
Stormwater Treatment
Measures
 Engineered systems that remove
pollutants from stormwater runoff
Media Filter (limited use for Special Projects)
Hydromodification
Management (HM) Facilities
 Reduce development-induced erosion
 Detain stormwater so that post-project
peak flows and durations match preproject conditions for a range of flows.
Hydromodification
Management (HM) Facilities
 Basins, tanks or vaults with specialized
outlet that slowly releases water.
Detention basin with specialized outlet
O&M Requirements
(Provision C.3.h)
 Agencies subject to the MRP must:
• Require facility owners to conduct ongoing
maintenance (e.g. , maintenance agreement).
• Prepare and implement plan for annual O&M
verification inspections, including new
installations.
• Conduct O&M verification inspections;
provide enforcement as needed.
• Track and report on inspections.
What about Municipalityowned Facilities?
 O&M inspection requirements do not
distiguish between municipal and nonmunicipal facilities.
 Inspect, track and report on facilities
that your municipality is responsible for
maintaining.
O&M Verification Inspection
Plan
 Begin implementing by 12/1/10.
 Each fiscal year, inspect:
• All newly installed stormwater treatment and
HM controls within 45 days of installation
• 20% of the total number of installed
stormwater treatment and HM controls (when
rounding, round up!)
• 20% of all installed vault-based systems (round
up)
 All installed treatment and HM facilities must be
inspected at least once every 5 years.
Lessons Learned from NOVs
 Round up when calculating 20 percent
of facilities per year.
• If your agency has fewer than 5 facilities, be
sure to inspect one per year.
Tools for Inspecting, Tracking
& Reporting
 O&M Verification Inspection Checklist
 Annual Report Table
 Each agency should have an internal
tracking table, which is NOT submitted
with Annual Report.
O&M Verification Checklist
Example Tracking Table
MRP Attachment G-1
DRAFT Annual Report Form
C.3.h Reporting Table
For More Information…
 Countywide Program Password Protected
ND page www.flowstobay.org (click on
“Municipalities,” then “ND”)
• O&M Verification Inspection Plan Template
• O&M Verification Inspection Checklist
• Model maintenance agreement
 Municipal Regional Stormwater Permit
www.flowstobay.org (click on
“Municipalities,” then scroll to “Municipal
Stormwater Permit”)
Common Issues in Inspections of
Newly-Installed Treatment
Measures
Laura Prickett, AICP, CPESC
EOA, Inc.
Construction Inspection Workshop
April 11, 2013
Outline

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Purpose of inspection
What to look for during inspection
Common issues
Checklist for 45-day inspection
Purpose of Inspection
 Verify treatment measures and/or
hydromodification management
controls are installed per approved
plans.
 At a minimum, inspect those
components that are visible in the
finished condition.
 If possible, also inspect below grade
components during construction.
Prepare for the Inspection
 Review project plans to identify:
• The number of treatment measures and/or
HM systems to be installed on the site.
• The locations of treatment measures
and/or HM systems.
• The dimensions of treatment measures
and/or HM systems.
Prepare for the Inspection
 Review project plans to identify:
• How high flows will be managed/diverted.
• Type and extent of plant cover.
• Type of approved irrigation system.
In this system, high flows will enter raised inlet.
During the Inspection
 Confirm that installation matches
approved plans regarding:
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Total number and type(s) of facilities.
Location of facilities on the site.
Dimensions of facilities.
Request confirmation from site
superintendent that biotreatment soil is
per MRP specifications.
During the Inspection
 Confirm that installation matches
approved plans regarding:
• Type and extent of plant cover.
• Functional irrigation system.
• High-flow bypass or overflow path.
Overflow drain designed to keep out trash and debris.
Common Issues
 Is there exposed soil?
• Exposed soil should be covered with 2” of
mulch, except for area immediately
surrounding tree trunks (roots need air).
 Will vegetation block inlets to the
treatment measure when mature?
Turf is blocking inlet; insufficient drop between
pavement and top of grade in planting area.
Common Issues
 Is there positive drainage to the
treatment measures?
 Is there permanent erosion control at
points of concentrated flow?
Cobbles reduce erosion at entrance to bioretention area.
Common Issues
 Are plants healthy?
 Accumulation of sediment from
construction activity?
• Accumulated sediment must be removed.
O&M Verification Checklist
May be used for 45-Day inspections; will have to
use “Comments” section
Thank you!
Laura Prickett, AICP, CPESC
EOA, Inc.
510.832.2852 x 123
[email protected]