1 Module 3: Typical Roadway Drainage Where it goes in Where it comes out Stormwater System Maintenance: A 4-Part Workshop Series 2 (Chart for illustrative purposes only, based on Best Professional Judgment of Southern RI Conservation District) 3 We will review Good Housekeeping Where stormwater enters our system: Inspecting and maintaining catch basins Minimizing erosion of shoulders and ditches Where stormwater leaves our system: Addressing scouring and excessive sedimentation at outfalls 4 We will Review the goals as written in the General Permit Clarify or expand as needed Review what we are doing now Review how we report our activities Look for ways to improve our effectiveness and/or efficiency 5 Inspecting & Maintaining Catch Basins 6 O&M Program Required Goal Procedures for implementing regular catch basin inspection & cleaning program Inspect all annually, document Clean as necessary Coordinate with illicit discharge detection Increase inspections in problem areas May request lesser frequency after 2 years documentation 7 Inspect, Document 8 SWMPP Pub. Info & EdPub. Part. Illicit Discharge Const. Runoff Post- Const Runoff Good Housekeeping 9 Locate system components outlet manhole Catch basin 10 How often to inspect? All catch basins annually for at least 2 consecutive years May request approval of lesser frequency based on documentation RIGL : at least once per year for those designated as prone to flooding or contributing significantly to storm water management problems 11 Maintain as necessary Remove trash Remove sediment when trap is 1/3 full Make necessary physical repairs Document activities and volumes 12 Our Catch Basin Procedures Maps Schedule Forms What to inspect Typical maintenance Database 13 Literature recommends Bring: Maps Camera Inspection/maintenance forms Pens Rod, tape or probe to measure depths Prybar to lift grates Cellphone for emergencies 14 Inspect, Document Trash & debris Estimate volume Sediment Measure depth Vegetation Note blockages Contamination Petroleum products Biohazards Structural integrity Nothing broken Pipes free-flowing Illicit connection 15 Estimating Sediment Volume Volume = area X depth Area typically = pipe size x 4 x 3.12 Total sump depth typically = pipe size x 4 Sediment depth = total sump depth distance from pipe invert to top of sediment 16 Infiltrating Catch Basins Dry wells No bottom and/or short lengths of pipe with no outlet Standing water indicates clogging 17 Safety Tips Wear appropriate safety equipment Use proper temporary traffic control Use care and proper equipment to lift grates & covers Dont enter a catch basin without proper training, and another person nearby 18 Minimizing Erosion of Shoulders & Ditches 19 O&M Program Required Goal Procedures to minimize erosion of road side shoulders & ditches by requiring stabilization Reduce velocity 20 21 Low Impact Development 22 Shoulder Problems 23 24 25 Size and velocity are important! 26 Rain Gardens & Biofilters NCSU-BAE 27 Our Procedures for Shoulders & Ditches Maps, database Schedule Forms Typical maintenance 28 Safety Tips Wear appropriate safety equipment Use proper temporary traffic control Be properly trained and familiar with equipment Dont leave edge drop-offs unprotected overnight 29 Locate potential problem areas Steep slopes Weak vegetation Un-foreseen areas of concentrated flow Un-planned vehicle pull-offs 30 Shoulder Repair Scoured areas should be filled and compacted Remove sediment/sand buildup when >3 higher than road 31 Select for salt tolerance, minimum maintenance 32 We dont want Purple loosestrife Phragmites 33 Ditch Maintenance Area of concentrated flow = Freshwater Wetlands Permit Work only in driest time of year Short sections at a time Start at outlet end, wait for it to stabilize 34 Recommended Practices Remove sediment build-up when 3 deep (about every 5 years) Restore infiltration in bottom by ripping with disc or roto-tiller 35 Recommended Practices Seed & mulch at the end of each day Install temporary check dams as needed If channel gullies persist size stone based on velocity, or Consider grade control structure 36 Any time youre out Note odors, sheen (illicit discharge) Watch impact of new curb cuts, culverts 37 Scouring, Excessive Sedimentation at Outfalls 38 O&M Program Required Goal Procedures to identify and report annually on scouring/excessive sedimentation at outfalls Procedures to remediate upon notification 39 SWMPP Pub. Info & EdPub. Part.Illicit DischargeConst. Runoff Post- Const Runoff Good Housekeeping 40 Outfall ID: Location: Description of Problem: Description of Remediation Taken, include dates: Receiving Water Body Name/Description: SECTION III.B Discharges Causing Scouring or Excessive Sedimentation (Part IV.B.6.b.1.v) 41 42 Note source 43 Note source 44 Our Procedures at Outfalls Maps, database Inspection Forms Reports Maintenance Schedules Typical outfall maintenance Reports 45 Outlet Protection 46 Outfall extensions Half-culvert Flexible Downdrain 47 Remove sediments with care 48 Retrofit opportunities 49 Typical Roadway Drainage Traditional Purpose: Remove runoff from the driving surface Good Housekeeping Purpose: Provide multiple opportunities for pollutants to be separated from runoff 50 Stormwater System Maintenance: Employee Training Brought to you by: This program was developed by the Southern Rhode Island Conservation District in partnership with the URI Cooperative Extension RI NEMO Program and the Rhode Island T2 Center. Funding was provided by the RI Department of Environmental Management and the RI Department of Transportation under the Phase II Stormwater Education and Outreach Project.