February 23, 2005 | General

Enhancing Agriculture With Biosolids Compost (France)

BioCycle February 2005, Vol. 46, No. 2, p. 66
A new cocomposting facility in Mont De Marsan services wastewater treatment plants in the region, and receives shredded yard trimmings from area municipalities.
Barbara Petroff and Karen Brashear

MONT de Marsan, France represents a colorful, unique region that vigorously shapes its future and successfully cultivates its past. From flamenco festivals and corridas to Armagnac and foie gras, this southwestern French community blends cultures and celebrates centuries-old traditions. Located less than 150 km (93 mi) from Spain, Mont de Marsan serves as the capital of Landes Department in France’s Aquitaine Region. The quaint town, rich in history, was founded in 1133 during the Capetian Dynasty. Yet, medieval structures and neoclassical architecture bear little evidence of the advancement in this environmentally progressive community.
Today agriculture, lumber and resins are the primary industries of the Landes Department. Until 200 years ago, the area was barren with shifting sand dunes and vast marshlands. In the 19th century, engineers stabilized the dunes, drained the marshes and implemented a major reforestation initiative. The resulting pine and oak trees now comprise one of Europe’s largest forests, and agriculture continues to progress.
As the agricultural industries evolve, so do the environmental regulations. In 2001, federal requirements, European Commission (EC) Directives and local farmers’ persistence for higher quality biosolids to apply to their loamy soils caused the community to search for a solution that would be ecologically sound and satisfy the distinctive criteria for the region. After visiting a state-of-the-art biosolids composting facility in North Carolina, community officials confirmed their decision to implement an in-vessel, agitated bin composting system that would use the same American technology to process biosolids and yard trimmings. The new French facility began operating in November 2004.
Project History
Biosolids have been managed via land application in this region for many years. Farm soils were comprised primarily of a sandy loam and lacked organic material. In an area known worldwide for foie gras, corn is an essential feed crop and the associated soil maintenance and enhancement are vital. Over the years, biosolids proved to be a valuable resource and the challenge was to determine what process and product would yield the most desirable and affordable results. Before 1997, there were no regulatory controls in France on spreading biosolids on agricultural land, which caused concern in the agricultural community that the soils were becoming contaminated. In 1998, France set biosolids standards for trace metals and trace organic compounds. Farmers in the South of France wanted to land apply biosolids that met a higher standard.
In April 2001, Syndicat Mixte Departemental d’Equipement des Communes des Landes (SYDEC), the regional utilities authority responsible for providing services to manage wastewater treatment plant biosolids and department green waste, conducted a study to determine the best alternative for managing biosolids and utilizing the end product. The study showed that composting biosolids with green waste and wood waste would create a product to greatly enhance the soil quality. In June 2003, SYDEC selected Veolia Water Systems/OTV-SUD Ouest, a division of Veolia Environnement, to design a composting plant that would use the USFilter IPS Composting System. Five months later, the project received environmental approval and administrative authorization to proceed.
Financing for the 8.05 million facility came from several sources. Agencies included Landes Counseil General (18%), European Union (20%), Agence de l’Eau Adour Garonne (20%), Agence de l’Environnement et de la Maitrise d l’Energie or ADEME (12%) and SYDEC (30%).
Connecting With Goldsboro, North Carolina
In December 2003, the SYDEC president, several officials, composting plant operators, and an OTV representative visited a biosolids composting facility in Goldsboro, North Carolina, which compost similar feedstocks using the same technology. (See “Wastewater Biosolids Management With Green Vision,” March 2004.) The visitors from Mont de Marsan wanted to tour the Goldsboro plant because the operations were similar in size, climate and terrain. And, like its French counterpart, Goldsboro also hosts a military installation, Seymour Johnson Air Force Base. The tour included the wastewater treatment plant’s dewatering system, the yard trimmings shredding operation and the composting facility. While in North Carolina, the SYDEC officials invited the Goldsboro representatives to visit the Mont de Marsan composting facility that would start up the following fall.
In November 2004, the Goldsboro utilities director traveled to Mont de Marsan, where she was able to apply her experience with the start-up and operation of the Goldsboro facility to the start-up training at Mont de Marsan. Before returning to the United States, the utilities director and her French counterparts discussed establishing a communication network that would enable the operators of the new Mont de Marsan plant to continue interacting with the Goldsboro staff.
New Facility with Old Charm
The Mont de Marsan biosolids composting facility is comprised of ten 45-meter (148-foot) long bays, the facility is designed to handle 44 tonnes/ day (48.5 tons) of dewatered biosolids at 15 percent solids concentration and 50 tonnes/day (55 tons) of green waste.
Mont de Marsan is centrally located to receive biosolids from the surrounding communities’ wastewater treatment facilities. Initially, approximately 30 wastewater treatment facilities will participate in the composting project. Trucks will transport dewatered biosolids from as far away as 100 km (62 mi). In an effort to accommodate wastewater facilities great and small, a mobile dewatering truck will serve five small plants that wish to participate in the project. “Although the composting plant has just begun operations, other wastewater treatment plants in the Landes Department area have expressed interest in bringing their biosolids here,” states Gerard Raynaud, SYDEC manager.
Wastewater treatment plants need to meet quality criteria in order to participate in the Mont de Marsan project. Each delivery truck that comes into the composting plant has a biosolids sample accompanying the load. The sample is retained by the composting facility for the duration of processing and until the end product is tested. If the end product fails the laboratory quality test, the original samples are analyzed to determine whether or not a specific treatment plant failed to meet the criteria for the biosolids delivered.
Each working day, trucks deliver biosolids and shredded green waste to the plant. Biosolids are deposited in an enclosed receiving pit, and shredded green waste is off-loaded into a covered storage area. The operator uses a front-end loader to place the green waste into a mixer located inside of the compost facility. The mixer is equipped with a load cell scale to ensure the proper biosolids to amendment material ratio. A grapple then transfers the biosolids from the receiving pit to the mixer. After blending, the mixture is conveyed to a concrete bunker where the front-end loader transfers the material to the beginning of the composting bays.
Once a day, the automated composting machine travels through each bay to mix and move the material about 4 meters (13 feet). At this rate, the compost is retained in the bays for 16 to 18 days before being transferred to the curing area where it matures for another 28 days. Although French regulations focus on specific standards for the end product and not on the actual process, the Mont de Marsan plant is required to achieve a minimum of 60°C for seven days to ensure that pathogen requirements for the final product are met. The bays are also equipped with an automated aeration system and a moisture addition system, to aid the composting process.
Odor control is imperative to the successful operation of the Mont de Marsan plant. Two chemical scrubbers and two large biofilters treat the facility’s process air. Pine trees surrounding the plant’s boundary provide an additional buffer between the site and its neighbors.
The Mont de Marsan facility has three operators and a supervisor. The finished compost initially will be used on cornfields. Under an agreement with the Department’s Chamber of Agriculture, 30 farmers will receive compost; SYDEC will pay for the first year’s hauling costs. The agricultural program is expected to increase public confidence in biosolids products, eventually leading to its use in civil works projects.
The French Regulatory Evolution
Biosolids composting is fairly new in France. In March 2004, the French ministers signed into law a new regulation for “sludge” compost. The new law, NFU 44095, recognizes composted biosolids as a product instead of a waste material. NFU 44095 is not a biosolids general standard. However, by comparison, the law decreases the allowable levels of many of the metals and organic compound standards established by the previous 1998 standards and added strict values for pathogenic microorganisms.
While France moves forward with its regulations, the European Commission (EC) issued other directives that support composting and beneficial use of biosolids. One directive involves a phased reduction in landfilling of biosolids. Another directive places land application responsibility upon the site owner. The EC also is sponsoring an initiative that will impact its 25 member countries. The proposal seeks to consolidate the Thematic Soils Strategy, Sludge Directive and Biowastes Directive into a single framework. French regulations, EC directives, and the EC proposed consolidated directive were among the many factors SYDEC officials considered when making decisions for a long-term regional biosolids management program.
The new composting facility will allow Mont de Marsan to increase its recycling goals and local farmers to receive higher quality biosolids. It is possible that the Mont de Marsan compost facility will be the model for meeting the new French NFU 44-095 biosolids regulations in other regions in France. These new regulations were the driving force to construct the biosolids composting facility in Mont de Marsan. The resulting compost will benefit both the farmers and the French citizenry in the long term by protecting the soil environment.
Barbara Petroff is the IPS Composting System project manager for USFilter, a Siemens company. Karen Brashear is the public utilities director of Goldsboro, North Carolina.
Composting In Shadows Of The “Stilt Walking” Tradition
ENVIRONMENTAL engineering transformed land, occupations and locomotion in Landes Department in France’s Aquitaine Region. Whether stilt walking in Europe originated in Flanders or Landes is an age-old question. Shepherds traversed the Landes marshlands on stilts for centuries before the 1900s. Stilts made passage easier through the extensive bogs and the elevation allowed a better view of scattered flocks. In 1891, stilt walkers of Landes earned international acclaim when their legendary Sylvain Dornon strode from Paris to Moscow, a distance of 2850 km (1830 mi) in 58 days. During this same era, marshes in southwestern France were drained, forests replaced pasturelands, and agriculture succeeded sheepherding. Stilt walking no longer served an occupational purpose. However, Landes people preserved their cultural legacy through folk dances that continue to be an integral part of community festivals.

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