Sheetflow Erosion Control Erosion Control for CESCL's

July 9, 2020

Fugitive Dust from Construction Projects

The Associated General Contractors of Washington developed the “Guide to Handling Fugitive Dust from Construction Projects” in 1997.  I edited it for the internet in 2009.

June 8, 2020

Construction Fugitive Dust

The classic brochure  created in 1997 by the  AGC of Washington and the Fugitive Dust Task Force.

I updated it for the internet in 2009.

May 15, 2020

Guide to Handling Fugitive Dust

Download: Guide to Handling Fugitive Dust from Construction Projects.PDF

The classic brochure developed in 1997 by the Associated General Contractors (AGC) of Washington Education Foundation and the Fugitive Dust Task Force, Seattle, Washington. Updated and edited for the Internet by: www.sheetflow.com, February 2009.

April 20, 2020

Environmentally Friendly, Biodegradable, Re-usable, and Recyclable Erosion and Sediment Control BMPs

I wrote this article for the April-May 2020 “Environmental Connections” magazine of the International Erosion Control Assn.  It starts on page 26.

Environmentally Friendly, Biodegradable, Re-usable, and Recyclable Erosion and Sediment Control BMPs

David Jenkins, CPESC

Erosion Control/Stormwater Engineer, Port of Seattle

Background

We have all seen silt fence left in place years after a project is completed, heard of birds and reptiles trapped in erosion blanket netting even after the straw and coconut mulch has biodegraded (1), and know of catch basin inserts and silt fence landfilled at the end of a project.

In 2015, the Port of Seattle (Port) rebuilt the center runway at Sea-Tac International Airport.  Silt fence was installed on the project perimeter-a total of nearly four miles.  Recyclers would not take the used fence and it ended up in a landfill. (2)

The Washington State Department of Transportation (WSDOT) keeps records of the total planned quantity of materials used on projects. From February 1, 2000 to February 1, 2020, the total planned quantity of silt fence used on WSDOT projects was 1,826,160 linear feet, or about 345 miles. Installed on both sides of Interstate 5, that quantity would run from Seattle, Washington to Portland, Oregon.  Based on my experience, the silt fence fabric likely ended up in a landfill or was left in place. (3)

The following are some means, methods, procedures and best management practices available to reduce the overall environmental impact of your construction projects. (more…)

Download: Environmental Connections, April-May 2020

Plastic mesh from straw wattle, five years after installation. Photo: David Jenkins

April 15, 2020

Guide to Handling Fugitive Dust from Construction Projects

Download: Guide to Handling Fugitive Dust from Construction Projects.PDF

The classic brochure developed in 1997 by the Associated General Contractors (AGC) of Washington Education Foundation and the Fugitive Dust Task Force, Seattle, Washington. Updated and edited for the Internet by: www.sheetflow.com, February 2009.

November 4, 2019

ESCA-BC 2019 Conference

I will be at the ESCA-BC 2019 Conference this week up in Coquitlam, British Columbia. I am giving two presentations and a contract specification workshop. This is a list of all of the Sessions.

I will be doing the following sessions:

Workshop

Writing Contract Specifications to Achieve Environmental Compliance Workshop

Presentations

Writing Contract Specifications to Achieve Environmental Compliance Presentation

Why Projects Fail to Meet Water Quality Requirements Presentation

September 17, 2019

Can’t Get Away From It

I can’t get away from it. It doesn’t matter where I go, I always see some type of construction erosion issue. I went to visit relatives in Portland, Maine, flying in and out of Boston Logan International. In the terminal, waiting for my flight back home, I saw a construction project on the ramp; it had rained a few says before, hard. Obviously, the stockpile had not been covered before the storm and sediment washed off the pile into the drain.

I work at an airport that operates under strict turbidity effluent limits; here is how we do this kind of work:

(1) rarely do we allow stockpiles on the ramp because we rarely reuse the excavated material (it is either contaminated, unsuitable or doesn’t meet current FAA requirements); it is direct loaded into trucks and hauled off. When we do stockpile, we place dirt on plastic and cover it with plastic, using lots of sand bags to secure it from jet blast and wind.

(2) work areas are always isolated so there is no runoff from the site. Normally, we use four-inch extruded asphalt curbing along the base of the jersey barriers. Rolled hot mix asphalt (HMA) is used at the entrance point so water is contained but vehicles can access the site.  Water that builds up inside the curbing is pumped back into the excavation if clean, or a tank if contaminated.

I should have mentioned that we also have strict sediment trackout requirements: no visible sediment leaves the site at any time.  This is both because of the effluent limits and for safety reasons; dirt and debris that gets sucked up into a jet engine is damaging and possibly deadly.

Lastly, I am not casting aspersions on the folks at Logan; I don’t know their situation, permits, drainage system, or tolerance for risk.  Because of my situation, I have low risk tolerance for potential non-compliance with our permit and I notice when something would cause me grief at my airport.

September 10, 2019

Preparing for Fall and Winter Rains

Preparing for Fall and Winter Rains

Winter is approaching, now is the time to get construction projects ready. Here are some things to consider:

Cover bare soil. Final grades can be covered with hydroseed, erosion blankets, topsoil, bark or whatever final cover is planned for the project.

Get your hydroseed contractor lined up now and avoid the October rush.

Don’t open up more than a few acres after September 1st.

Grades that aren’t being actively worked can be covered with straw at a rate of 1500 pounds per acre. This is a very cheap and effective way to protect bare soil from raindrop impacts and erosion. Hand seed before spreading the straw. Spray it with water to help hold it in place.

Track your slopes with a Cat: up and down slope, not across slope. The first helps prevent erosion, the second speeds it up.

Use flex pipe drains at bridge ends if your permanent drainage system and curbs are not in place. Collect the water from the bridge using sand bags and divert it to the pipe. Make sure the pipe is long enough to reach the bottom of the slope.

Use a water truck and water seeded areas weekly to get quicker growth. The better the growth going into winter the better.

If you have to open up a large area, only clear and grub small areas. You can clear larger areas if you don’t grub. Roots and slash help protect the bare soil.

Walk the site looking only at erosion controls, thinking ahead of areas that could have a problem. Identify them and start making additions and corrections.

Locate all existing water flows in and around your project and find out where they drain to.

Think about maintenance and regular inspection of erosion controls. When are silt fences going to be inspected and who does it? Who removes mud from check dams? Who covers slopes with straw or other mulch?

Get materials on site now. Again beat the rush for materials in October and November when everyone is in a panic to get plastic and straw. Stockpile enough straw, plastic, silt fence, flex pipe, sand bags, seed, rock, now to cover all areas that are bare.

Set up emergency procedures now. Who should be called in emergencies? Do you have a WSDOT certified Erosion and Spill Control Lead? Brief your personnel on what to do if they see muddy water and who to go to.
Make sure that erosion control material installers know proper installation methods.

Make sure all your silt fence is installed on contour with the ends flared up slope a few feet. If it is not on contour, identify the lowest points of the fence as these will be the failure spots. Install a double row of silt fence at these low spots before you have a failure. Double up your silt fence in areas where eroding slopes could flow into wetlands or streams.

Do you have bare spots where previous seeding hasn’t grown? Cover it with seed and straw if the area is small, remobilize the hydroseeder for larger areas.

Make sure all catch basins within the project boundary are protected with inserts, fence surrounds, or other methods to keep mud out. Locate any catchbasins outside project boundaries that may receive water from your site and protect them.

Make sure that you have a copy of the Stormwater Site Plan (SSP) and Temporary Erosion and Sediment Control plan (TESC) and any grading or environmental permits on site in the job shack. Know what they say. Give each inspector a copy of the SSP and TESC to keep in their truck. These are working copies that can be adapted to site conditions.

Modify your permanent stormwater ponds into temporary sediment ponds by installing a standpipe and blocking the outlet with sand bags. Cut a few small holes in the standpipe to allow for slow release of water. You can also use perforated pipe as the standpipe and hold it in place with “T” posts, wire, and gravel piled up around it.

Use geotextile fabric as a temporary ditch lining to protect bare soil from erosion. Hold the fabric in place with rock check dams, wooden stakes, or sand bags.

Make sure that all check dams are installed so that the top center point is lower than the bottom end points. This prevents endcutting. You may have to add more material to the dam to increase the width, especially on wide ditches with shallow grade side slopes

July 20, 2019

Diversion Berm

Photo: David Jenkins

I am always looking for products and materials that achieve the goal of environmentally friendly erosion controls, such as this reusable water-filled diversion berm.

Specification
Materials

A. Berm shall be a minimum 6 inches high and 10 feet long and made of 10 mil polyurethane or 22 oz. PVC.

Construction Requirements
Water Filled Diversion Berms

a. Berms shall be installed such that offsite water is prevented from entering the job site and site water is kept within the project boundary.
b. Berms may be used to prevent contaminants and water from entering catch basins.
c. Berms may be used on impervious surfaces.

Payment
O. Payment for “TESC – Water Filled Diversion Berms” will be made at the contract unit price per each per month as stated in the Schedule of Unit Prices, and shall be full compensation for furnishing the specified diversion berms. The unit price per each shall include the cost of mobilization/demobilization, cleaning, hauling and all incidentals for the number of diversion berms required by the Engineer for the duration of the contract.

July 2, 2019

Biofence Specification

I am trying to get to 100% biodegradable, recycled, reusable, recyclable, low impact best management practices.  I have used burlap fabric fence several times.  I use it whenever I can leave it in place to degrade, like on habitat or wetland work. 

Biofence Specification

Materials
BIOFENCE
A. Biofence shall consist of 7 ounce or heavier uncoated burlap fabric at least 36 inches wide and 100 feet long. Wood stakes dimensions shall be a minimum 1 1/8 x 11/8 inches by 42 inches high.

Construction Requirements
 BIOFENCE
a. Stakes shall be driven into the ground a minimum of 12 inches and be spaced no more than 6 feet apart.
b. Fence ends shall be joined by wrapping ends together around a post 3 times and driven into the ground.
c. Burlap fabric shall be attached to the post in at least 3 places using staples or other method approved by the Engineer.
d. When used as a barrier fence, fabric shall not be trenched into the ground. When used as a silt fence, a minimum 8 inch flap shall be left at the bottom and held in place with straw wattles staked in as detailed in item 9 above.

Payment
C. Payment for “TESC – Biofence” will be made at the contract unit price per linear foot as stated in the Schedule of Unit Prices and shall be full compensation for furnishing all labor, equipment, materials and tools necessary to complete the installation of the biofence as detailed on the drawings or as directed by the Engineer and specified herein. The unit price shall include all maintenance, the removal of biofence, and restoration of the area at the completion of the work

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