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
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:
•
•
•
•
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]