Operation Maintenance of Permanent Stormwater Controls Overview of

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 Lprickett@eoainc. com