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 pre- project 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 Municipality- owned Facilities?  O&M inspection requirements do not distiguish between municipal and non- municipal 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 (click on “Municipalities,” then “ND”) O&M Verification Inspection Plan Template O&M Verification Inspection Checklist Model maintenance agreement  Municipal Regional Stormwater Permit (click on “Municipalities,” then scroll to “Municipal Stormwater Permit”)  May conduct as part of overall final inspection of constructed project UNLESS: Stormwater treatment and/or HM facilities become operational earlier, IN WHICH CASE — Inspect and approve stormwater facilities before they become operational

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 x 123