Operation & Maintenance of Permanent Stormwater Controls Overview of Inspection Requirements

1. Operation & Maintenanceof Permanent Stormwater ControlsOverview of Inspection Requirements Laura Prickett, AICP, CPESC EOA, Inc. Construction Inspection Workshop April 11, 2013

2. 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…

3. Permanent Facilities that Require O&M Inspections • Provision C.3.h of the MRP requires agencies toconductinspectionstoverifyoperation & maintenance (O&M) of: • Stormwatertreatmentmeasures, and • Hydromodificationmanagementmeasures

4. Stormwater Treatment Measures • Engineered systems that remove pollutants from stormwater runoff Bioretention Area (biotreatment)

5. Stormwater Treatment Measures • Engineered systems that remove pollutants from stormwater runoff Media Filter (limited use for Special Projects)

6. Hydromodification Management (HM) Facilities • Reduce development-inducederosion • Detainstormwater so that post-projectpeakflows and durations match pre-projectconditions for a range of flows.

7. Hydromodification Management (HM) Facilities • Basins, tanks or vaults with specialized outlet that slowly releases water. Detention basin with specialized outlet

8. 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.

9. WhataboutMunicipality-ownedFacilities? • O&M inspectionrequirements do notdistiguishbetween municipal and non-municipal facilities. • Inspect, track and reportonfacilitiesthatyourmunicipalityisresponsible for maintaining.

10. O&M VerificationInspection Plan • Begin implementingby 12/1/10. • Each fiscal year, inspect: • Allnewlyinstalledstormwatertreatment and HM controlswithin 45 days of installation • 20% of the total number of installedstormwatertreatment and HM controls (whenrounding, round up!) • 20% of allinstalledvault-basedsystems (round up) • Allinstalledtreatment and HM facilitiesmust be inspected at least once every 5 years.

11. Lessons Learned from NOVs • Round up whencalculating 20 percent of facilities per year. • Ifyouragency has fewerthan 5 facilities, be suretoinspectone per year.

12. Tools for Inspecting, Tracking & Reporting • O&M VerificationInspectionChecklist • AnnualReportTable • Eachagencyshouldhaveaninternal tracking table, whichis NOT submittedwithAnnualReport.

13. O&M VerificationChecklist

14. Example Tracking TableMRP Attachment G-1

15. DRAFT Annual Report FormC.3.h Reporting Table

16. 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”) • 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

17. Common Issues in Inspections of Newly-Installed Treatment Measures Laura Prickett, AICP, CPESC EOA, Inc. Construction Inspection Workshop April 11, 2013

18. Outline • Purpose of inspection • What to look for during inspection • Common issues • Checklist for 45-day inspection

19. Purpose of Inspection • Verifytreatmentmeasures and/orhydromodificationmanagementcontrols are installed per approvedplans. • At a minimum, inspectthosecomponentsthat are visible in thefinishedcondition. • Ifpossible, alsoinspectbelow grade componentsduringconstruction.

20. Prepare for the Inspection • Reviewprojectplanstoidentify: • Thenumber of treatmentmeasures and/or HM systemsto be installedonthesite. • Thelocations of treatmentmeasures and/or HM systems. • Thedimensions of treatmentmeasures and/or HM systems.

21. 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 thissystem, highflowswillenterraisedinlet.

22. During the Inspection • Confirmthatinstallationmatchesapprovedplansregarding: • Total number and type(s) of facilities. • Location of facilitiesonthesite. • Dimensions of facilities. • Requestconfirmationfromsitesuperintendentthatbiotreatmentsoilis per MRP specifications.

23. During the Inspection • Confirmthatinstallationmatchesapprovedplansregarding: • Type and extent of plantcover. • Functionalirrigationsystem. • High-flow bypass oroverflowpath. Overflowdraindesignedtokeepouttrash and debris.

24. 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.

25. 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.

26. Common Issues • Are plants healthy? • Accumulation of sediment from construction activity? • Accumulated sediment must be removed.

27. O&M VerificationChecklistMay be used for 45-Day inspections; willhaveto use “Comments” section

28. Thank you! Laura Prickett, AICP, CPESC EOA, Inc. 510.832.2852 x 123 Lprickett@eoainc.com