1. Low Impact Development Training Maintenance & Monitoring: Environmental & Facility Managers Presented by: The Low Impact Development Center, Inc. A non-profit water resources and sustainable design organization www.lowimpactdevelopment.org

2. Copyright 2009 Low Impact Development Center, Inc. Objectives Maintenance for Bioretention, Pavers, Green Roofs, Filter strips and buffers Corrective Actions General Environmental Monitoring

3. Copyright 2009 Low Impact Development Center, Inc. Regulatory requirement –NPDES MS4 permit –Other State storm water regulations (new) –Documentation may be required Necessary to continue function as designed Proper maintenance lowers long term costs Less costly to maintain than repair or replace Maintenance Drivers

4. Copyright 2009 Low Impact Development Center, Inc. Maintenance – Bioretention Primary maintenance requirement - regular inspection and repair / replacement of damaged components Can be incorporated into regular landscaping maintenance contract, as the routine periodic maintenance for bioretention areas is similar to what is required of any landscaped area

5. Copyright 2009 Low Impact Development Center, Inc. Planting Maintenance Routine maintenance should include a biannual health evaluation of the plantings, and removal and replacement of any dead or diseased vegetation. The use of native plant species in the bioretention cell will reduce fertilizer, pesticide, water, and overall maintenance requirements. Level of pollutants in the soil can become toxic, impair plant growth Maintenance – Bioretention

6. Copyright 2009 Low Impact Development Center, Inc. Maintenance – Bioretention Planting maintenance Immediately after installation, water plant material for 14 consecutive days (unless sufficient natural rainfall). When trees have taken root, or at least by 6 months, remove stakes and wires Visually inspect vegetation for disease or pest problems at least once in the spring, once in the fall, and more frequently in the summer. If treatment is warranted, use the least toxic approach During extended drought, look for physical signs of stress (unrevived wilting; yellow, spotted or brown leaves; loss of leaves, etc.). Water in the early morning if needed Prune excess growth annually in the spring and throughout the growing season if desired. Trimmed materials may be recycled back in with replenished mulch or landfilled if there is a concern of heavy metals accumulation. Weed regularly, as necessary

7. Copyright 2009 Low Impact Development Center, Inc. Maintenance – Bioretention RequirementsTestingRemediation Soil pH should be between 5.5 and 6.5. Obtain a kit and instructions from the State Cooperative Extension Office. Apply the necessary amount of limestone to get the pH in the correct range. Soils Visually inspect and repair erosion at inflow points once in the spring and once in the fall, at a minimum. Use small stones to stabilize erosion along drainage paths. Check the soil’s pH once or twice a year. Apply an alkaline product, such as limestone, if needed.

8. Copyright 2009 Low Impact Development Center, Inc. Maintenance – Bioretention Soils - Maintain Infiltration Rates Runoff from impervious surfaces is directed to bioretention cells to infiltrate through the soil medium Once the infiltration capacity of the soil medium is exceeded, storm water begins to pool at the soil’s surface Ponding should only last 4-6 hours Mosquitoes larva need 4+ days of standing water

9. Copyright 2009 Low Impact Development Center, Inc. Soils – Corrective Action Depending on pollutant loads, soils may need to be replaced within 5-30 years of construction. If standing water consistently over 4-6 hrs: –Clear the underdrain of potential clogs –Check filter fabric above the underdrain –Remove mulch and rake surface to remove surface blockages –Last resort - remove the soil mixture Before removing soil mixture, analyze for clay content and hazardous content If greater than 15% clay content, then: –Temporarily block end of discharge pipe, install appropriate E&S controls –Carefully dig up plants so that root systems are maintained (and return to cell following soil replacement) –Remove soil and dispose appropriately as clean fill or in an approved landfill –Inspect pipe and gravel layer, if pipe is clogged, then wash the gravel layer with a high-pressure hose – this should clean the pipe –Place new soil in the cell and replant vegetation Maintenance – Bioretention

10. Copyright 2009 Low Impact Development Center, Inc. Maintenance – Bioretention Mulch Layer Uniformly applied approximately 2 to 3 inches deep. Do not pile the mulch around trees or other plantings Fresh bark mulch (either standard landscape fine shredded hardwood mulch or hardwood chips). Make sure it is free from weed seeds, soil, roots or any other substance not consisting of bole, branch wood, or bark Do not use grass clippings as mulch Every 6 months, in the spring and fall, add a fresh mulch layer. Once every 2 to 3 years, in the spring, remove the old mulch layer before applying the new one

11. Copyright 2009 Low Impact Development Center, Inc. DescriptionFrequency 1. Soil a) Inspect and Repair ErosionSpring and fall b) Check pHOnce a year 2. Organic Layer a) Re-mulch any void areasAs needed b) Add new mulch layerSpring and fall c) Remove old mulch layerThree (3) years 3. Plants a) Water plant material for fourteen consecutive days after planting has been completed unless there is sufficient natural rainfall Immediately after Completion of project b) Remove stakes and wires after six monthsAfter rooting c) Inspect for disease/pest problemsSpring/summer/fall d) Treatment of diseases As needed, refer to manufacturer Maintenance Schedule – Bioretention

12. Copyright 2009 Low Impact Development Center, Inc. 3. Plants (continued) e) Removal and replacement of all dead and diseased vegetation considered beyond treatment Spring and fall f) During times of extended drought, look for signs of stress Water as needed. Summer g) Weed and prune excess growthSpring/summer h) Fertilize As needed, refer to manufacturer i) Remove tagsAfter warranty 4. General a) After major rainstorms, inspect site and make sure drainage paths are clear and that ponding water dissipates over time. Clear the drainage path of any accumulated sediment or debris. Seek remediation if drawdown times are consistently much longer than 4-6 hours After major rainstorms Maintenance Schedule – Bioretention

13. Copyright 2009 Low Impact Development Center, Inc. Maintenance – Permeable Pavers Primary maintenance requirement - clean the surface drainage voids Can be incorporated into regular street sweeping program Annual inspections

14. Copyright 2009 Low Impact Development Center, Inc. Inspections Routine maintenance is key: –Conventional street sweepers equipped with vacuum sweepers and high-pressure water can used to restore permeability –Street sweeping frequency varies depending on drainage area inputs (leaf debris, erosion, etc.). An active street sweeping program in the site’s drainage area will also help to prolong the functional life of the pavement –If necessary, add additional gravel chips to fill pore spaces after vacuum sweeping In case of localized settling, individual paver blocks can be removed, new gravel added, and the blocks replaced Maintenance – Permeable Pavers

15. Copyright 2009 Low Impact Development Center, Inc. Restrict use by heavy vehicles Limit use of de-icing chemicals and sand Implement stringent sediment control plan Failure of systems: –poor design –inadequate construction techniques –low permeability soils –heavy vehicular traffic –resurfacing with nonporous materials Maintenance – Permeable Pavers

16. Copyright 2009 Low Impact Development Center, Inc. Maintenance Schedule Permeable Pavers DescriptionFrequency Initial InspectionsMonthly for first several months following construction Vacuum sweeping and high pressure hosing 4 times/year Encourage active street cleaning in the site’s area Regularly Annual inspectionsYearly, after large storms Fill potholes and cracksAs needed Address spot-clogging problems by drilling holes As needed

17. Copyright 2009 Low Impact Development Center, Inc. Maintenance – Permeable Pavement Routine Maintenance Similar to permeable pavers Recommended: Vacuum sweep twice per year

18. Copyright 2009 Low Impact Development Center, Inc. Maintenance – Permeable Pavement Corrective Action Fill potholes and cracks with permeable patching mixes Fix spot clogging by drilling ~0.5-inch holes through the porous pavement layer every few feet

19. Copyright 2009 Low Impact Development Center, Inc. Virtually maintenance free Periodic inspections of system components Most important - ensure spigot is set to slowly release the barrel’s water Maintenance – Rain Barrels & Cisterns

20. Copyright 2009 Low Impact Development Center, Inc. Bimonthly inspection: –rain barrel is free of debris –filtration screen and downspout not clogged –overflow system properly directing the water away from siding and foundations and not causing erosion problems –mosquito screen properly installed Once a year, wash the barrel with mild (preferably biodegradable) soap and water Maintenance – Rain Barrels & Cisterns

21. Copyright 2009 Low Impact Development Center, Inc. Corrective Action There are few mechanical parts on cisterns or rain barrels Spigot, valve, and screen replacements can be ordered from the manufacturer Cracked rain barrel = replace rain barrel Large cisterns constructed out of materials such as metal or concrete may need repairs to walls by parging (for concrete) or welding (for metal) Maintenance Schedule – Rain Barrels & Cisterns

22. Copyright 2009 Low Impact Development Center, Inc. DescriptionFrequency Make use of the stored water!Regularly Check for clogging of the entrance/outlet pointsEvery other month Check for proper diversion of the overflow systemEvery other month Check for proper installation of the mosquito screen Every few weeks in the summer Wash the barrel with mild soap and water Annually, preferably in the spring Prepare the system for winter conditionsPre-freezing Maintenance Schedule – Rain Barrels & Cisterns

23. Copyright 2009 Low Impact Development Center, Inc. The maintenance requirements for street tree-box filters are similar to those of other bioretention devices, although less complicated Maintenance – Street Tree-Box Filter

24. Copyright 2009 Low Impact Development Center, Inc. Inspections Bimonthly If possible, conduct during or immediately after a rain event Debris removal: –Inspect system and clear drainage path of accumulated leaves, debris, and trash –Remove accumulated materials on the top layer of the soil media, test, and dispose –Inspect discharge pipe for clogging and clean if necessary Maintenance – Street Tree-Box Filter

25. Copyright 2009 Low Impact Development Center, Inc. Maintenance – Street Tree-Box Filter Planting Maintenance Same maintenance as bioretention cells Soils Maintenance Same maintenance as bioretention cells Runoff bypassing the tree-box = clogged inflow area, or reduced infiltration properties of soil mixture Soils analysis, disposal requirements, and corrective measures are the same as bioretention cells For remediation assistance, contact Americast at (800) 999-2278 or (804) 798-6068

26. Copyright 2009 Low Impact Development Center, Inc. First two years of maintenance typically included with the purchase of single and multiple-unit tree box filters –These would include removal of trash, debris and sediment, replenishment of the mulch, and care or replacement of plants Annual maintenance = $500 per unit (performed by the manufacturer) or $100 per unit (performed by the owner) (sample cost estimate based on the Filterra™ Stormwater Bioretention Filtration System.) Maintenance – Street Tree-Box Filter

27. Copyright 2009 Low Impact Development Center, Inc. Corrective Actions Plants may have to be replaced because: –they have overgrown the filter –environmental stress –they are mistaken as weeds growing through the grate, and are removed Maintenance – Street Tree-Box Filter

28. DescriptionFrequency 1) Overall system a) Inspect and clear drainage pathsEvery other month 2) Plants a) Water plant material for fourteen consecutive days after planting has been completed unless there is sufficient natural rainfall Immediately after completion of project b) Inspect for disease/pest problemsSpring/summer/fall c) Treatment of diseasesAs needed, refer to manufacturer d) Removal and replacement of all dead and diseased vegetation considered beyond treatment Spring and fall e) During times of extended drought, look for signs of stress. Water as needed. Summer f) Weed and prune excess growthSpring/summer 3) General a) During major rainstorms, inspect site and make sure that infiltration is occurring as expected. Every other month. b) Clear the top layer of soil of accumulated materialAs needed c) Clean the drainage pipesAs needed d) Seek remediation if infiltration function is not adequate after cleaning efforts As needed Maintenance Schedule - Street Tree-Box Filter

29. Copyright 2009 Low Impact Development Center, Inc. Maintenance - Dry Wells Minimal maintenance: –Clearing the rain gutters of debris that could clog the downspout Corrective Actions: –Can clog over time if there is extensive loading of fine- grained sediment –Standing water at the surface indicates clogging –Dig out gravel, then excavate to remove sediment and uncover a layer of soils that has sufficient infiltration capacity

30. Copyright 2009 Low Impact Development Center, Inc. Maintenance - Filter Strip Incorporate into landscaping contract Inspect twice annually for erosion or damage to vegetation Additional inspections after periods of heavy runoff Requires mowing, irrigation, and weeding Mowing may only be necessary 1x or 2x per year for safety and aesthetics or to suppress weeds and woody vegetation Periodic litter removal, and always prior to mowing

31. Copyright 2009 Low Impact Development Center, Inc. Maintenance - Vegetated Buffers Maintenance Program Monitor and manage to maintain maximum water quality benefits and, where desired, wildlife habitat benefits Inspections – at least annually, and always within a few days after severe storms. Look for evidence of sediment deposition, erosion, or development of concentrated flow channels Aggressive weed and invasive species control Avoid working in riparian area between April 15 and August 15, when a variety of animals are bearing their young Corrective Actions –If the buffer width is sufficient, Changes in hydrology, drought, over-grazing or natural disasters such as flooding or fire may require the replanting or reestablishment of the buffer

32. Copyright 2009 Low Impact Development Center, Inc. Maintenance - Grassed Swales Maintenance Objectives: Keeping up the hydraulic and removal efficiency of the channel Maintaining a dense, healthy grass cover Maintenance Program: Periodic mowing (with grass never cut shorter than the design flow depth) Weed control Watering during drought conditions Reseeding of bare areas Clearing of debris and blockages Corrective Actions: Remove cuttings from the channel Remove accumulated sediment Avoid applying fertilizers and pesticides

33. Copyright 2009 Low Impact Development Center, Inc. Maintenance - Infiltration Trenches Maintenance Objectives: Prevent clogging, which may lead to trench failure Maintenance Program: Inspect annually Monitor observation well to confirm trench is draining properly Inspect after large storm events Remove accumulated debris or material Stabilize surrounding areas to eliminate the potential for sediment clogging Corrective Actions: If infiltration trench fails, remove clogged stone and sediment Wash stone to remove sediment and replace

34. Copyright 2009 Low Impact Development Center, Inc. Maintenance - Green Roof Maintenance requirements for a properly installed, well established vegetated roof are minimal: Inspection of roof membrane, the most crucial element of a vegetated roof Inspection and preventive maintenance of the drainage layer flow paths

35. Copyright 2009 Low Impact Development Center, Inc. Maintenance - Green Roof Corrective Actions More complex systems may have monitoring devices incorporated into the membrane Leak detection systems can be brought to the site to locate breaches in the membrane The soil media can be removed & the membrane repaired Long periods of drought or loss of soil to high winds may require replacement of the media or replanting Schedule supplemental watering during drought periods, or install an irrigation system

36. Copyright 2009 Low Impact Development Center, Inc. Stormwater Management Feature Maintenance Contracting and $ Sustainment (UT/SRM) funds must be used, NOT Environmental Enter your SW features into iNFADS - NAVFAC Portal - Account request Partner with PW to get your SW features maintained SOW, GCE Landscaping contract, BOS contract, new Regional Stormwater Maintenance Contract (?)

37. iNFADS

39. Copyright 2009 Low Impact Development Center, Inc. Monitoring Programs Not typically a regulatory requirement Potential requirement for discharges to sensitive or impaired waters Monitoring plan shaped by regulatory requirements, site characteristics, parameter(s) of concern, and use of the data

40. Copyright 2009 Low Impact Development Center, Inc. Water Quantity Monitoring Monitor the effectiveness of LID features either on a small scale (individual features) or large scale (stream flow): Small Scale Manual or automatic sampling methods can be used to calculate flow rates upstream and downstream of a LID feature, based on the depth measured using a weir or a rate of flow measured using a conveyance device. Large Scale Where LID features are being installed as retrofits in already developed areas, the effectiveness of the retrofits can be assessed by comparing pre-LID and post-LID flow rates downstream.

41. Copyright 2009 Low Impact Development Center, Inc. Water Quality Monitoring The same pre- and post-LID samples taken for small scale water quantity monitoring can be used for water quality monitoring The Nationwide Urban Runoff Program (NURP) has identified the following “standard pollutants characterizing urban runoff”: PollutantAbbreviation Suspended Solids ConcentrationSSC Biochemical Oxygen DemandBOD Chemical Oxygen DemandCOD CopperCu ZincZn Total PhosphorousTP Soluble PhosphorusSP Total Kjeldahl NitrogenTKN Nitrate + NitriteNO2 + NO3 Water Quality Monitoring Parameters

42. Copyright 2009 Low Impact Development Center, Inc. Training Stormwater Training for facility personnel ECATTS Web-based environmental training by media Approximately 20-min each Courses: Stormwater – Basic Information Stormwater – Comprehensive Overview Wetlands Spill Prevention Control and Countermeasures Spill Response and Notification http://navfac.ecatts.com Password = “navfac” Stormwater Training for Facility Managers

43. ECATTS