COMPOST-BASED EROSION AND SEDIMENT CONTROL DEMONSTRATIONS

BioCycle October 2003, Vol. 44, No. 10, p. 32

Demonstration sites in the Metro Atlanta region provide hands on education and training and visual proof of the effectiveness of compost-based BMPs.

Britt Faucette, Wayne King and Peter Germishuizen

THE environmental benefits of diverting organics previously destined for landfills speaks for itself but far more important are the benefits being derived from using these organics to engineer soil and design functional landscapes that protect Georgia's natural resources - most important of which is water. Historically, Metro Atlanta as well as other heavy urbanized areas in Georgia, has lacked for a comprehensive water management plan and a soil management strategy. Population growth has dramatically changed the landscape and the environment. These changes include a loss of tree cover, reduced green space, and increased impervious surfaces. After suffering several years of consecutive droughts, Metro Atlanta now experiences flooding and combined sewer overflows with almost every major rain event. Denying access of precipitation to the soil and landscapes and rushing storm water downstream using conventional curbs and gutters has had a serious impact on water quality and quantity in Georgia.
These realities have created an opportunity for outreach and education on using compost-based best management practices (BMPs) as a core component of functional soil and landscape systems in storm water management and land planning. The Georgia Green Industry and the Georgia Composting Association have teamed up with other stakeholders, regulators, architects, engineers and the University of Georgia's Engineering Outreach Service to carry out field demonstrations of these BMPs. These systems not only provide storm water benefits such as groundwater recharge and cleaner streams, they also increase the urban forest, reduce the urban heat island, improve air quality, reduce stream pollution and provide a more aesthetically pleasing and sustainable environment. This article provides an overview of some of these field demonstrations.

OUTREACH TO GEORGIA DOT
A demonstration site was established by the Georgia Composting Association to feature at the BioCycle Southeast Conference in August, 2001. Located along the Chattahoochee River and adjacent to Atlanta's perimeter/ I-285 beltway in Cobb County, this site also was intended for use by the Georgia Department of Transportation (GDOT) for evaluation on how compost blankets and filter berms perform over time. Demonstrations provided during the conference tours included compost blanket and berm applications using composted biosolids and peanut hulls (ERTH Food) furnished by ERTH Products LLC and poultry litter compost from Georgia Natural. Cobb County and the city of Smyrna provided additional compost and equipment. Equipment demonstrations and applications included blower trucks (Rexius and Metro Mulch Blowing Services) and a filter berm and blanket builder (Mill Creek Manufacturing).
Composted biosolids/peanut hulls blankets and berms were established in three test plots - 1-inch seeded, 2-inch unseeded, and 2-inch seeded. A Filtrexx Filter Sock filled with the same product was placed at the base of each plot. Additionally, a mixed particle size mulch blanket and filter berm plot, a hydroseeded plot, a bare soil plot with silt fence, and a bare soil plot with a filter sock were installed. A storm water collection bucket and sampler/monitor was placed at the base of the silt fence plot and at the base of the 2-inch seeded compost blanket and filter sock plot.

Results from the first storm event (3-inches ) showed much of the hydroseed and sediment from that plot had washed away leaving the upper quarter of the plot with no cover. The storm water collection device showed that no runoff left the 2-inch compost blanket/filter sock plot while the 5-gallon collection device at the base of the silt fence plot was nearly full of sediment. No rilling was evident in the compost or mulch blanket plots, while significant rilling was apparent in the bare soil and hydroseeded plots. Over two years later, and with numerous intense rain events, these plots continue to provide evidence of the effectiveness of compost as a storm water management tool. GDOT has visited this site on many occasions since it was established to further evaluate the effectiveness of these systems.
GDOT also established three other demonstration/test sites on Highway 53 extension north of Atlanta. The first two sites used poultry litter compost blankets exclusively (Poultry Gold, Georgia Natural and Gromor Organics) on a 3:1 slope and a 2:1 slope. All plots were seeded with a rye and Bermuda grass mix. Finn and Metro Mulch pneumatic blower trucks were used for the application. The third demonstration site featured Poultry Gold compost filter berms using a Mill Creek Berm Builder. All products performed well.

CONSTRUCTION SITE DEMOS
Beers/Skanska USA: A commercial construction company owned by the Swedish company Skanska, Beers/Skanska USA is building a new wastewater treatment facility north of Atlanta adjacent to the very popular Mall of Georgia. Traditional BMPs were being used both for slope stabilization and to trap sediment around the storm runoff intake drains to the sediment pond. The company was having difficulty establishing vegetation on the slope, which in turn blew out the system installed to trap sediment. ERTH Products installed filter socks around the catch basin, which performed very well in areas where they were installed. It also installed a seeded compost blanket around the entire rim of the slope to demonstrate that vegetation could be established no matter where it was applied on the face of the slope. Despite the success of the demonstration, the engineers would not allow a change order for the installation of compost blankets needed to protect the slopes (versus just the rim). The filter socks eventually filled up with sediment, but could have continued to perform well if money had been budgeted for their maintenance. The lesson here is that these compost-based BMPs must be installed as systems to perform properly.
Habitat For Humanity Global Village: Located in downtown Americus, this 6-acre site is a future model village for “smart development.” The Habitat for Humanity International Global Village & Museum will feature environmental landscape designs, a local market, a cultural museum, a winding watercourse, and pedestrian friendly pathways - all within the design of the residential neighborhood.
Storm water management and erosion control were key issues at the inception of this project, and alternative measures such as compost were included in the erosion and sediment control designs. This particular construction site had a history of problems with erosion caused by surrounding impervious surfaces and downhill drainage. The compost blankets were used to control erosion and to improve the soil structure, as part of a larger program designed to use engineered soils and landscape systems to offset impervious surfaces and retain storm water on site.
Compost filter berms were constructed using the ERTH compost screened to half-inch minus. The berm dimensions were 2-feet wide by 1-feet high. Eight and 12-inch filter socks were filled with the compost and used as ditch checks. The socks also were used in lieu of silt fences and in a stream bank retaining wall. Compost blankets were installed with filter berms and filter socks throughout the project site. The blankets were seeded and application rates varied from a half-inch to 1-inch depths. This was a very successful project from start to finish. After experiencing several problems early on with land disturbing activities, the use of compost berms and blankets and socks “saved the day.” Compost was also used as a soil amendment in most of the landscaping to capture and retain the pollutants associated with the storm water coming off of the parking lots and other impervious surfaces.
Glenwood Green: Located in Grant Park, a neighborhood of Atlanta, Glenwood Green is an apartment complex with approximately 100 new apartments that were in various stages of construction in May 2002. Although erosion and sediment control BMPs were employed, the construction site had high rates of storm water runoff due to surrounding impervious surfaces as well as excessive amounts of sediment discharge from the site's retention/detention pond, according to the city of Atlanta. Area storm drains had to be cleaned out and alternative measures adopted to manage the storm water more effectively, as mandated by city officials.
Polyacrylamide was initially suggested to stabilize the disturbed soil, however compost was ultimately the new BMP measure adopted. A 1-inch thick compost blanket was pneumatically applied to the exposed soil surfaces to reduce runoff and prevent soil erosion, while filter socks were placed around storm drains to filter any moving sediment and prevent it from reaching the drains. Compost blankets and filter berms were also used in lieu of silt fences to prevent sediment from entering streets and parking areas.
The ERTH compost was used to provide the temporary soil stabilization necessary for this project; it also was used later for permanent vegetation and final landscaping projects at the apartment site. Because this site was on grade and in the final stages of building and landscaping, it proved to be an excellent example of how compost could be used like a mulch to stabilize the soil during the final stages of construction - and how the same application of compost could later be incorporated as a soil amendment in preparation for the sod and landscapes. A later evaluation of the site revealed that areas where the compost was applied provided a dense green grass cover with good roots and water retention, as compared to some areas where the sod was laid over a base of compacted clay.
Clayton County Constructed Wetlands: The Clayton County Water Authority has contracted with ERTH Products and ERTH Environmental Partners to provide erosion and sediment control for the construction of the Huie Phase One Wetlands project, an $8 million, 90-acre constructed wetlands project to treat wastewater. The Clayton County Water Authority plans to build five large bioretention cells that will process the county's wastewater through biological filtration and specially adapted plant species within these cells before it goes through a final treatment phase and ultimately released back to area reservoirs. CH2M Hill is the engineering firm providing the design for the project and has specified 16,500 cubic yards of compost to establish vegetation to provide temporary and permanent stabilization on the banks around the wetlands for erosion and sediment control during site construction. Clayton County has experienced problems in attempting to vegetate slopes using traditional hydroseeding and ended up with rills and gullies. Another concern was the fertilizer and nutrient release associated with the hydroseeding application getting into the wetlands. Using compost for a one time application to establish vegetation was less risky in their eyes.
The Huie project also provides a good example of closed loop recycling: Biosolids from the Clayton County Wastewater Facility are processed at ERTH Products manufacturing facility and the biosolids compost is being returned to Clayton County to be used in the constructed wetlands project that will be used to process their wastewater. Clayton County is also considering using the compost and organic matter in its storm water management programs and for erosion and sediment control associated with the installation of the storm water sewer pipes and infrastructure.

ADDITIONAL DEMONSTRATION SITES
Rayonier Paper Products: Rayonier Paper Products produces specialty paper products for clients like NASA and the U.S. military. As part of a comprehensive waste management plan, the company composts its paper fiber, a by-product of the manufacturing process. While waste reduction and the subsequent cost avoidance is the goal of Rayonier's composting efforts, some energy has been put into marketing the finished product. Two demonstration sites were set up on their property to show how the compost could be used for erosion and sediment control on sandy soils. Both were street embankments, one pitched at a 2:1 slope and the other a 1.5: 1 slope. While much of the compost did hold to the 1.5:1 slope, this was probably its steepness threshold. The compost applied to the 2:1 slope performed quite well.
Gromor Organics: In the fall of 2002, Gromor Organics Inc. and the Georgia Composting Association sponsored a Compost Field Day to coincide with the annual Sunbelt Agricultural Expo in Moultrie. There were two main objectives of the field day; to demonstrate the production and utilization of compost blankets and filter berms to a group of visiting Russian farmers, and to demonstrate and promote the use of compost as an erosion and sediment control BMP to state legislators. Speakers from the University of Georgia addressed the farmers on the use of compost in the production of vegetable seedlings and on compost blankets and filter berms.
For demonstration purposes, compost blankets were established on a 2:1 slope; the filter berms were installed around the contour of the slope's base. Compost blankets were seeded with rye grass and applied at a depth of 1- to 1.5-inches. The filter berms were approximately 2-feet high by 3-feet wide at the base. The grass established quite with nearly 100 percent cover with no visible erosion on the compost blanketed slope. A section of the slope used as a control (no compost or seed) had significant rilling by visual inspection.
City Of Griffin: The City of Griffin has recently set up a 30-acre demonstration site to evaluate the use of new and innovative measures in storm water management. Five field plots 50-feet by 100-feet with modest slopes ranging from 3.5 to 10 percent have been established to evaluate these techniques. Seeded ERTH compost blankets and filter berms are being evaluated as well compost-filled Filtrexx filter socks (which are being compared to sediment fences and straw bales as an alternative sediment trapping device).
One demonstration in the city of Griffin was done at the Oakview Detention Pond. Integrated Science and Engineering contracted with ERTH Products through an EPA 319 grant to demonstrate how innovative and performance based BMPs can be used to increase biodiversity and soil stabilization around retention/detention ponds in the city. The retention/detention pond had 100-foot long slopes slightly greater than 2:1. Compost blankets were applied with a pneumatic blower at one-inch depths and seeded with a rye, wheat, Bermuda grass mix. During the first part of the project, the seed was incorporated in the compost and blown on but shortly thereafter the seed/injection equipment failed and the compost was blown on and then the seed was applied using a conventional hand spreader. There was no significant difference in the amount of vegetation established in both applications.

For comparative purposes, a standard geotextile mat with hydroseed was applied next to the seeded compost blankets. After three months, significant rilling was evident underneath the geotextile mat and none was evident in the compost blanket. Additionally, the blanket produced a near 100 percent vegetative cover while the hydroseeded mat had nearly 50 percent, according to visual inspection by project managers. The site continues to be used for educational and demonstration purposes on the effectiveness of compost as a temporary and permanent vegetative erosion and sediment control measure. Britt Faucette is Organics Recycling & Compost Specialist with Engineering Outreach at the University of Georgia, Athens. Wayne King, Sr. manages ERTH Products LLC, based in Peachtree City, Georgia. Peter Germishuizen is with Gromor Organics, Inc. in Tifton, Georgia. In addition to the supporters/participants mentioned in this article, others include the Pollution Prevention Assistance Division of the Georgia Department of Natural Resources, Georgia Soil and Water Conservation Commission, Rockdale County, Gwinnett County, Bobo Grinding, WoodTech Mulch, US Poultry and Egg Association and the Animal and Poultry Waste Management Center at North Carolina State University.

SPECIFICATIONS AND RESEARCH
CURRENTLY, five composting operations in Georgia have used their products in erosion and sediment control applications at nearly 15 demonstration sites. Four companies have established themselves as compost applicators for erosion and sediment control. Three county government agencies have requested demonstration sites to be set-up in their county.
The Georgia Department of Transportation has approved the use of compost for erosion and sediment control and is currently developing appropriate specifications. The Georgia Soil and Water Conservation Commission (the state agency charged with approving and publishing best management practices for erosion and sediment control) is considering including compost in its next edition of Erosion and Sediment Control in Georgia.
The University of Georgia's Engineering Outreach Service, Department of Biological and Agricultural Engineering, Institute of Ecology and Department of Crop and Soil Sciences are collaborating on a two-year study to evaluate the use of compost for erosion and sediment control and its effects on water and soil quality and plant growth compared to selected industry standard measures. While the widespread adoption of compost in this relatively new application may seem laggard, the interest and support network it has generated in a relatively short time period is not only impressive but vital to its forward movement in being an approved equal or better in the erosion and sediment control industry.

Copyright 2003, The JG Press, Inc.