Construction Land Disturbance Pollution Control Employee Training Series Green Country Stormwater Alliance (GCSA) May 19, 2017 Time to discuss land disturbance practices and look at some good and bad examples. Prepared by INCOG

Land Disturbances Utility repairs water and sanitary sewer lines This presentation provides suggestions for: Utility repairs water and sanitary sewer lines storm drain system Street repairs Sidewalk construction and repairs Landscaping (parks, buildings, medians) Power pole installation and replacement There are a number of things you can do to lessen the impact these activities have on storm water quality.

Land Disturbances Keeping chemicals, dirt and debris out of the storm drain system will reduce water pollution. The curb to the left is funneling everything into the storm drain. Dirt and sand all around the drain waiting to be washed in. The pipe discharging right into the storm drain. Lots of problems here.

Land Disturbances Two silt fences won’t work if they are not maintained. Notice the vegetation growing on the silt. This has been going on for sometime. 4

Land Disturbances Notice how the sediment has built up to the point the curb is buried. Water is cutting a channel through the island of sediment in the road and has washed away the downstream portion of the island. Notice the particle size. This isn’t just fine silt. There have obviously been volumes of water flowing across this site. Up-gradient from this silt fence is a very large area of cleared ground on a fairly steep slope. 5

Land Disturbances These photos were taken on May 5, 2008. This construction site is in a corner where two roadside ditches come together and go through a tube under the street.

Land Disturbances These photos were taken on June 20, 2008 (43 days later) at the same site. This is the same site 43 days later. Still the same problems, only worse. 7

More bad examples and the reason hay/straw bales are no longer allowed.

Good examples

Land Disturbances Note: Projects that disturb one acre or more must comply with the state’s OKR10 storm water permit for construction activities. If a permit is required, your supervisor, stormwater or environmental coordinator will provide specific instructions.

Land Disturbances All projects must be managed to prevent or reduce soil or other pollutants from being washed into storm drains, creeks or lakes. In addition to soil, other potential pollutants on construction sites include trash, debris, oil, grease, lime, concrete truck wash water, etc. When you do site inspections, just look around. Many problems are obvious. Check the site after a significant rain and see what is washing off of the site. Then decide if it is a problem. If so, find the source and come up with a solution.

Definitions Erosion - the removal or wearing away of soil due to the action of water (or wind). Sediment - soil particles that settle out of flowing water. A bank erosion problem and a silt fence being overwhelmed. At this point, the bank could use some resurfacing work to fill the gullies and smooth it out. Then matting or netting to hold the soil in place and seed it to get vegetation growing.

Erosion Typical stream bank erosion problems.

General Principles Preventing erosion is more effective than trying to remove sediment from runoff (source control). Minimize the amount of disturbed area. Divert runoff or flowing water away from disturbed areas. Use mulching, matting and netting to help hold soil in place and establish vegetation as soon as possible. Roll out sod in critical areas when you don’t have time to wait for seeds to sprout and grow.

General Principles Locate dirt stockpiles out of the street and away from runoff or flowing water to prevent sediment from washing into storm drains. Cover stockpiles or provide a barrier such as a berm or silt fence around the pile.

Best Management Practices Best Management Practices (BMPs) are tools used to reduce or prevent water pollution. Erosion Control BMPs are used to protect disturbed soils from being washed off by rainfall and/or runoff. Sediment Control BMPs are used to trap sediment carried by runoff and keep it on the construction site. Waste Management BMPs are good housekeeping practices to control trash, chemicals and debris. Erosion control – measures used to help keep the soil in place or prevent the movement of soil. Sediment control – measures used to trap and remove soil from flowing water. Catch it before it leaves the site. It can then be put back where it came from. Waste management – measures used to keep chemicals, trash and debris off the ground and out of the stormwater.

Best Management Practices Erosion Control BMPs: Vegetation - grasses or other plants that provide erosion protection. Mulching - a layer of straw, wood or synthetic material that covers the loose soil. Plant roots help hold the soil in place and the leaves lessen the impact of rain drops and help slow the flow of surface water. Mulch helps serve the same purpose if vegetation is absent or sparse.

Best Management Practices Erosion Control BMPs: Erosion control blankets - mesh matting made of straw, wood fiber or plastic. Plastic sheeting - may be used for short-term protection of disturbed areas or dirt stockpiles.

Best Management Practices Sediment Control BMPs: Sediment Pond – a pond used to detain water and allow sediment to settle out. Silt fence - filter fabric trenched into the soil and attached to supporting posts. The bottom portion of the silt fence should be buried to keep water and silt from running under. Metal stakes and a wire backing make the fence much stronger than wood stakes alone.

Best Management Practices Sediment Control BMPs (continued): Triangular sediment dike - filter fabric placed over welded wire shaped into a triangle. These BMPs are designed to allow the passage of water, but detain sediment.

Best Management Practices Sediment Control BMPs (continued): Inlet protection – Concrete blocks and stone placed around or in front of a storm drain inlet. These BMPs are designed to allow the passage of water, but detain sediment.

Best Management Practices Waste Management BMPs: Debris and trash control - use covered trash cans, bins and/or roll-off boxes for debris and trash disposal. Keep trash cans and dumpsters handy so people will not be as inclined to throw trash on the ground.

Best Management Practices Waste Management BMPs: Chemical management - follow proper material storage and spill cleanup procedures for chemicals used on construction sites. A galvanized water tank is being used as secondary containment. It is simple, inexpensive and effective. Spills or leaks will be contained and easy to clean up if they occur.

Best Management Practices Waste Management BMPs: Concrete washout - capture wash water from concrete truck cleaning at designated locations to prevent wash water runoff from entering the storm water system. Wash water is frequently discharged into a pit or low area on site. Water will then evaporate and seep into the soil leaving the cement to set. When the cement is set, it can be hauled off. This will keep the washout cement from setting up in your storm sewers and the particulates out of the creeks.

Preventing Storm Water Pollution: What We Can Do Protecting water quality requires that all employees do their part to prevent storm water pollution.