Presentation on theme: "It’s only a raindrop, what is there to worry about !"— Presentation transcript:
1It’s only a raindrop, what is there to worry about ! Presentation 5 OutlineImplementing Construction/Post-Construction Do’sand Don’tsTerms and ConceptsPermit ComparisonReview of What is RequiredHow Do I Know What to Use Where or When?- Key Selection Decision PointsStorm Water Pollution Prevention Plan- Do’s and Don’tsQuestions and AnswersIt’s only a raindrop, what is there to worry about !Session 5 Implementing Construction/Post-Construction Do's and Don'ts
2Terms and Concepts We Need to Know Municipal Separate Storm Sewer System (MS4) PermitBMP- Best Management Practices.MCM-Minimum Control MeasuresMEP- Maximum Extent PracticalPhase II regulated areas – Area regulated by OEPA requiring Storm Water Management Plans (SWMP) and Best Management Practices.Construction Storm Water PermitSWP3- Storm Water Pollution Prevention PlanNOI-Notice of IntentWQV – Water Quality VolumeWQV = C*P*(A/2)C = Run-off coefficientP = 0.75” Precipitation DepthA= Area draining into BMP (acres)Session 5 Implementing Construction/Post-Construction Do's and Don'ts
3Permit ComparisonMunicipal Separate Storm Sewer System (MS4)- Phase II PermitCompared WithConstruction General Permit (CGP)What does the Construction General Permit mean to MS4’s?Becomes process for construction and post- construction MS4 permit.
4Permit Comparison – What is Required MS4Construction Activities over 1- AcreErosion and Sediment – Ordinance, regulationsDevelop measurable goalsConstruction operator requirements.Structural and Non-Structural BMP’sBMP Appropriateness AssessmentCGPConstruction Threshold Acreages:- 1 to 5 acres- Flexible- Over 5 acres- PrescriptiveSWP3- RequiredOnly Structural BMP’s identified in permit.Non-Structural BMP’s not allowed under CGPNotice of Intent (NOI) to be submittedStatewide Permit2008 Renewal date
5Permit Comparison – When is it Required MS4For Construction Activities over 1- AcreFor new or redevelopment projectsFor compliance w/ Construction and Post-Construction Minimum Control Measures.CGPFor Construction activities over 1 Acre:- 1 to 5 acres- Over 5 acresFor new or redevelopment projectsTo address Construction and Post – Construction site storm water run-off.
6Permit Comparison – How will they be Implemented MS4Develop sub-division regulations, ordinances.Develop Site plan review checklistDevelop inspection and training programReview current Erosion and Sediment control requirements.CGPDevelop erosion and sedimentation control planDevelop SWP3 plansNew and re-development projects.Through Developer, contractor and third parties.
7How do I know what BMP to use where or when? Do’s and Don’ts when deciding on Post-Construction Structural BMP’s:Do:Review OEPA permitSeek professional advice or guidance from regulatorsTalk to your neighborsAsk how much will it cost and what is the level of maintenance.Do Not:Just call out 1 of the 8 mentioned in the permit.Ignore maintenanceBe afraid to ask for assistanceWhat did I do to deserve this?
8Structural Post Construction BMP’s Vegetated filter strips and swaleFunctional BackgroundTreats storm water through the interaction of vegetation and removal of suspended solids.Can be used exclusively or used as pretreatment to additional BMPs.Swale areaPolaris Parkway, Westerville, Ohio – Ohio Department of Transportation
9Structural Post Construction BMP’s Infiltration BMP’sBackgroundTreat storm water through a filtering substrate (sand, gavel, or soil).Discharges into the ground water.Requires the correct soils and geology to ensure success.Basin Infiltration AreaCaltransODNRInfiltration trench area
10Structural Post Construction BMP’s Extended detention basin (Dry Basin)Detention AreaBackgroundCapture and release the WQv slowly over 48 hours (requires an outlet control structure).Requires overflow spillway for larger than design storm events.Two methods are available:Above ground – Preferred method when feasible.Below ground – Useful in urban situations.Ohio Department of Natural Resources
11Structural Post Construction BMP’s Retention basin (Wet Basin)Retention AreaBackgroundCapture and releasing 75% of the WQv slowly over 24 hours (requires an outlet control structure).Provides permanent storage for 75% of the WQv.The full storage depth ranges from 3-6 feet (volume must be less than 15 Ac-ft).Requires overflow spillway for larger than design storm events.Ohio Department of Natural Resources
12Structural Post Construction BMP’s Bio-retentionBackgroundTreats storm water via a special planting soil.Uses an underlying perforated underdrain or storm sewer as an outlet.Native plant material such as trees, shrubs, and grasses give the appearance of normal landscaping.Designed to store 75% of the WQv prior to filtration.Total filtration should occur within 40 hours.Bio retention areaWarren Co. SWCD
13Structural Post Construction BMP’s Constructed WetlandBackgroundTreats storm water through bio-retention interaction.Defined as a depressed heavily planted area that is designed to maintain a dry weather flow depth ranging from 0.5 to 2 feet.Detain and release WQv between 24 hours. Requires the use of an outlet control structure.Constructed WetlandOhio Department of Transportation
15Review of Post- Construction Requirements Post-Construction Requirements w/in Construction General PermitRequirements/ObjectivesMaintain Stream Functions.Protect Stream Chemical, Physical and Biological Characteristics.Provide perpetual management of Runoff quality and quantityBMP-Maintenance PlanStorm Water Pollution Prevention Plans (SWP3)Anticipated Impact Rationale to include;Quantity = FlowChannelsFloodplainMorphologyHydrologyWater Quality2 Different PermitsConstruction Site Storm Water Permit- Effective April 21, 2003.Transportation 2006Municipal Separate Storm Sewer System (MS4)- Permit- Effective March 10, 2003.Post-Construction Minimum Control Measure
16Storm Water Pollution Plans- SWP3- Do’s and Don’ts Submit NOI to OEPA w/ feeDevelop SWP3 and keep on siteUnderstand who is responsible- Developer and ContractorRecognize benefit of sequencingObtain a copy of OEPA’s SWP3 ChecklistLearn from othersDevelop internal plan review checklist for SWP3 elements.Due engage an engineer as necessaryDue understand level of maintenance associated with each BMP selected.
17Storm Water Pollution Plans- SWP3- Do’s and Don’ts SWP3 Don’ts:Forget to account for off site drainageForget to perform weekly and ½” rainfall site inspectionsForget to document inspectionsForget to include Sediment and erosion control planForget to develop maintenance plan for each BMP selected or designed.Forget need to evaluate and assess Post-Construction- accessibility will be key
18Local /ODOT road projects Local road project- Follow local requirements for post-construction controls.ODOT – Project incorporate ODOT post-Construction policy
19Post Construction BMP FAQ’s Are post-construction BMP’s required on projects from 1-5 acres?Yes, requirements more flexibleWhat types of BMP’s are required?Local requirements- MS4, TMDL, etc.OEPA not specific requirements, recommendLimiting impervious areasReduce impervious connectivity\Preserve buffers around streams/wetlands
20Post Construction BMP FAQ’s Are any projects exempt from Post-Construction BMP’s:Yes, Linear projects which do not create impervious surfaces.Redevelopment projects less stringentPublic transportation projects 3 year extension –March Must still comply with Sediment and erosion control component of this permit.- NOI and sediment and erosion control plan required.
21SWP3 and Post Construction Summary Storm Water Pollution Prevention PlansBMP’s to implement- construction and postDetailed maintenance planDetailed site plan: description, run-off calculationsLocation of BMP’sSediment and erosion control planSupporting narratives in general notes or on plan, copy of permitBMP installation/construction sequenceControl of non-sediment pollutant planCompleted NOI/ with $200 feeBMP-installation specificationsPost-construction BMP’sAuthorized signature
22Reference ResourcesUrban Runoff Quality Management – ASCE, WEF Manual of practice no. 23, ASCE Manual and report on engineering practice no. 87.WebsitesOEPA-www.epa.state.oh.us/dsw/storm/index.htmlODNR-FHWA -ODOT - www. dot.state.oh.us/stormwater/NEMO -
23We need to better understand the power of the raindrop! Presentation 5 ReviewImplementing Construction/Post-Construction Do’s and Don’ts:Terms and ConceptsPermit ComparisonReview of what is requiredHow do I Know What to Use Where or When?- Key selection decision pointsStorm Water Pollution Prevention Plan- Do’s and Don’tsQuestions and AnswersWe need to better understand the power of the raindrop!Session 5 Implementing Construction/Post-Construction Do's and Don'ts
24Questions and AnswersI think the presentation will end here. We can use the next few slides if they ask us questions about themThis slide should suggest “URS” any ideas??Session 5 Implementing Construction/Post-Construction Do's and Don'ts
25Session 6 – Good Housekeeping/Pollution Prevention Basics and Tools End of Session 5Session 6 – Good Housekeeping/Pollution Prevention Basics and Tools