Home Sustainable Land Development Today February 2005

Texas-Style Erosion Control

Written by Greg Yoko

Wednesday, 02 February 2005

Compost now utilized on all types of land development projects. When you have the Texas Association of Builders (TAB), the Texas Department of Transportation (TxDOT), and the Texas Commission on Environmental Quality (TCEQ) each choosing the same solution to solve erosion control issues, it is a pretty good sign that the solution is a good one. Now, if the rest of the country would just catch on, many NPDES (National Pollutant Discharge Elimination System) requirements for construction runoff and storm water management issues could be resolved more efficiently and effectively. Not a Garden Variety Solution The solution being implemented in Texas is compost. However, this isn’t the compost cooked up in your parents’ backyard to throw on the garden over the winter. “Too many professionals in the land development industry still relate composting to the garden. We need to take composting from a garden landscaping luxury to an infrastructure necessity,” said Stacie Johnson, Composting Specialist with Chamness Technology. The state of Texas is leading the way with further implementation of this natural technology. In fact, TxDOT is the largest single consumer of commercial compost in the world. This past June (2004), TxDOT applied its one-millionth cubic yard of compost. The utilization of compost, while only showing slight relative growth, is beginning to gain universal acceptance. “This is clearly a change from the status quo,” said Scott Plett, a member of the United States Composting Council. “Everybody knows and understands how to do a silt fence. Developers and engineers are familiar with and accept the use of silt fences, topsoil, and their limitations. Making a decision to go with something different, like compost, will take education and research.” Among the compost products are seeded ‘blankets’ of compost and rich topsoil, erosion-control ‘tubes’ filled with compost, and ‘berms’ (mounds) of organic material to help remove silt from stormwater flows. All three are used to control erosion by establishing vegetation in damaged soil. The application type depends on the project objective. While DOTs in Connecticut, Iowa, Texas, and Washington have documented success within the past few years, it was a 1998 partnership between TxDOT and the TCEQ that enabled the measurement and evaluation of a large range of compost usage. “The compost alternative,” explains Barrie Cogburn, a landscape architect with TxDOT, “is comparable in cost to topsoil, but provides a more effective solution to the erosion problem by adding organic matter to poor soils as a soil amendment so that revegetation can occur.” In addition to preventing erosion, compost, which is comprised of a variety of recycled materials, provides environmental, economic, and performance benefits. It reduced the maintenance requirements of the state’s right-of-ways and the repeated efforts to revegetate erosion-prone areas that increase the cost of projects. “As you might imagine, by the time a road project gets to the final phase, revegetation,” reveals Cogburn, “because of heavy compaction, we are left with less than optimal conditions for vegetation establishment. The use of compost has proven to be an invaluable solution.” In fact, engineers with TxDOT have researched and are now selectively implementing the idea of utilizing compost to maintain the moisture level along pavement edges to mitigate pavement cracking. “We have found that treating the soil next to the pavement dramatically reduces soil shrinkage that causes the pavements to crack,” states Richard Williammee, P.E., Ft. Worth District (TxDOT) Materials Engineer and Research Project Director. Over a two-year period, 17 test plots were studied over a 1300-foot stretch of highway northwest of Stephenville (TX) in Erath County. Four variables were used. In addition to testing two types of compost (biosolids and dairy manure), application depths of 2 and 4 inches and widths of 5 and 10 feet were placed. Of course, a control section was also utilized. Following installation and after 18 months of observation, the use of the biosolid compost at a 4-inch depth and 10-foot width illustrated the best results - absolutely no developing cracks. “It is anticipated,” states Williammee, “that the cost of compost placement will be measurably less than the cost of filling the pavement cracks with asphalt to seal out water from the underlying soil thus causing swelling or void problems. An on-going evaluation of the 17 test plots will give us an excellent view of the longevity of the composts’ effectiveness.” He also explained that when the road construction process is evaluated, the results make a lot of sense. “Contractors utilize moisture to get the maximum compaction to ensure as stable a foundation as possible. After that, we pave it and seal it. There is no design to keep the moisture stabilized so eventually the soil along the pavement shrinks and propagates underneath, causes the pavement to crack and then we provide regular sealing to fight the continued cracking process to keep the underlying pavement structure intact.” Research will continue as implementation at TxDOT also continues. A recent grant is enabling three additional test sections in TxDOT’s Lubbock, Bryan, and Corpus Christi Districts—this time to measure the effect with different soil types and some other compost and climate variables. Wider Acceptance — From Transportation to Subdivisions One of the barometers of the increasing use of compost technology is the number of vendors now approved to provide product to TxDOT. “The number of vendors that have attained product certification (Seal of Testing Assurance Certified through the U.S. Composting Council Program) has doubled over the past couple of years,” says Cogburn. A larger supply usually indicates an increased demand. In fact, some compost producers are turning away business because they cannot keep up with the demand. “We turn work down every day,” claims Don Legacy, owner and president of J-V Dirt + Loam (Austin, TX). “The business we do with our existing customers is so rapidly expanding, we have to limit the expansion of our customer base.” Legacy, who added compost installation to his soil and gravel business about 12 years ago by accident, says that it now represents the majority of his business. In fact, J-V Dirt + Loam was the 2004 recipient of the Small Business Environmental Excellence Award for the development of the compost methods. In being recognized for the company’s contribution, the Texas Commission on Environmental Quality stated that “Don Legacy does his homework.” Road building and new construction often aggravate the natural process of erosion. Legacy and the team at J-V Dirt conducted numerous demonstrations to promote innovative solutions. The company established methods to remove thousands of tons of organic materials from Texas landfills and endangered watersheds by arranging to have the material composted, seeded, and applied to eroding soils around the state, developing new techniques to reduce water runoff. “Compost became the core of our business about 10 years ago,” explained Legacy. “Over that time, we worked on perfecting our process and products, basically inventing the best way to meet the erosion control and stormwater management needs through the use of an environmentally friendly and effective solution.” Recognized as the inventor of Texas methods for utilizing seeded compost for erosion control and re-vegetation, JV Dirt + Loam secured the approval of the TCEQ for a new, proprietary design using vegetated erosion mats to replace the rock down chutes for a landfill in Avalon, Texas (Ellis County). Jeff Davis, with the Municipal Solid Wastes Permits Section of TCEQ, explains that the landfill down chutes are always susceptible to severe erosion. Industry tests have illustrated that utilizing the erosion mats would significantly reduce, if not eliminate, the situation. The erosion mats are produced by J-V Dirt + Loam by placing its compost mixture with the unique environmental fabric produced by North American Green. The proprietary design, and its TCEQ approval, was a collaborative effort of Legacy, Lone Star Products (the Texas distributor for North American Green) and Gregg Adams, P.E of Briggs and Mathews Environmental. “I worship the ground they walk on,” says Legacy of North American Green. “They are the only producer of fabric that we use and Lone Star Products provides us with the necessary fabric designs. It is the only product that meets our needs as well as the stringent regulatory requirements for landfill down chutes. The fabric reinforces the turf and can withstand 12 pounds of sheer stress per inch.” Legacy, who is a former builder and developer, sees the growth of compost applications at residential and subdivisions construction sites. “Some of our largest projects in 2004 were new home subdivision developments in need of remedial erosion controls and re-vegetation. As enforcement of storm water regulations on the industry expands, so will this part of our business,” says Legacy. That use will likely continue to increase largely due to a new TCEQ program initiative which was just approved for an Federal and State grant from the EPA and includes participation by the Small Business and Environmental Assistance Division (SBEA), Texas Association of Builders (TAB), Texas Department of Transportation (TxDOT) and the Lower Colorado River Authority (LCRA) to conduct regional workshops and demonstrations. This new grant follows a sequence of cooperation in the TxDOT and TCEQ partnership that included a 2000 EPA grant award also initiated by Scott McCoy, TCEQ Program Specialist. With the newest grant, the message of compost usage will expand to a new market—builders and developers. The TAB boasts a membership of over 10,000 and 31 chapters statewide. The first goal of the partnership is for the SBEA composting staff, along with TAB, to provide educational information and demonstrations to their membership on the utilization of best management practices (BMP) involving compost/mulch erosion control blankets, filter berms, and filter socks. Application of these BMPs will assist in the reduction of erosion, stormwater runoff volume and total suspended solids in Texas construction projects, specifically urban and subdivision developments. It has been projected that Texas will lose 500,000 acre-feet of water reservoir capacity by 2050 according to the Texas Water Development Board. This loss of capacity will be caused entirely by the increase in sedimentation from Texas rivers and streams. Permitting and enforcement of the Texas Pollution Discharge Elimination System (TPDES) is the responsibility of TCEQ. As of March 2003, stormwater Phase II permitting dramatically affected land development in the state of Texas for construction activities that disturb more than one acre of land. If BMPs are not properly installed, maintained, or do not perform, the permit holder may be subject to fines and/or incarceration. For this reason, all interested parties will need to know about BMP’s for controlling erosion, including full-cost associated with installation and maintenance. University research has shown these alternative BMPs to be up to 99 percent effective for the removal of total suspended solids from stormwater runoff. To accomplish this goal, SBEA, TAB and other interested parties will conduct 28 workshops and 28 demonstrations on the use of compost/mulch BMPs across the state. In addition, two workshops and demonstrations with the Lower Colorado River Authority will be held on the use of compost/mulch BMPs. Another objective is to increase awareness with the other disciplinary professionals involved in the land development process. Therefore, the groups will also provide “brown bag” workshops to consultants, designers, developers, governmental agencies, associations and other interested parties. SLDT