Privatization and Upgrades at a Waste Water Treatment Plant

T Teamwork and Technology Makes Class A Biosolids Production a Reality herma- Fli te At Work

Privatization and Upgrades at a Waste Water Treatment Plant Servicing a Government CDP Uncovers a Class A Solution Anne Arundel County, MD - Since 2010, when American Waters Military Services Group contracted to operate a waste water treatment plant at a government census-designated place, the project was moving toward producing a Class A biosolids end product. The facility had been spending handsomely to haul wet solids to farm fields in neighboring states from its secluded Maryland home base, adjacent only a refuge and a stretch of freeway. To arrive at Class A capabilities, AWMSG existing nitrification process required integration with the right technology.

Focusing on cost savings and ecological impact issues, they developed a three pronged exit strategy for the anticipated Class A product which includes utilization of a local hauler for low-cost land application, sales to local farms and sales to a local cement kiln as a low-grade coal replacement.

American Waters Military Services Group’ privatization project of its Maryland waste water treatment plant brought to light the many complexities and challenges of Class A production.

A coalition of talent and technology has moved the project forward and a successful conclusion is anticipated by Spring of 2013. A key component: Therma-Flite’s IC Bio-Scru Dryer.

National Trends. Local Laws. The American Waters project is in keeping with the broad national trend toward Class A biosolids.

The East Coast, with its dense urban population centers, is the bellwether for the Class A movement, as Class B land application is rapidly becoming not viable. AWMSG’s privatization project is also resonant with public policy in the state of Maryland, where the Chesapeake watershed is fiercely protected and phosphate regulations are stringent. In Maryland, the push towards Class A is popular with constituents who are both ecoconcerned and watchful of rising utility costs.

HDR, Engineering, Inc., Therma-Flite and Bowen Engineering Corp.: A Triumvirate for Change. Bowen Engineering Corp. of Laurel, MD would ultimately be responsible for the physical construction of the numerous upgrades at the AWMSG facility. From Bowen’s perspective, bringing everyone together on the front end of the project would be essential for them to bring the project in on time and on budget. Pre-planning began with information gathering from probable subcontractors, consultants and the Maryland Department of the Environment. Because of the myriad of complexities, Bowen wanted comprehensive input and teamwork from the start.

HDR Engineering, Inc kicked off with a 6-month study to create a master plan, beginning with improvement of the collection process to service the 100,000 total users. The study encompassed research to identity the best technology to produce Class A, diversification of its handling in anticipation of likely regulatory change. As HDR investigated the many possible technologies (pasteurization, alkaline stabilization, dryers, centrifuges), they developed the 5-point criteria by which they would be ranked: chemical costs, reliability, end product disposal options, capital outlays and ease of operation. When the research began, HDR was leaning toward lime pasteurization but operation and maintenance costs, power requirements, etc., changed their thinking. All things considered, HDR recommended a biosolids dryer. AWMSG then collected several proposals for drying systems of various designs. In the end, Therma-Flite’s IC 3600 mid-sized dryer, with 2-ton per hour sludge processing capability, was selected.

Therma-Flite’s Class A, PRFP, Bio-Scru Dryer. Continuous feed, with minimal variation in processing temperature, Therma-Flite dryers are an effective, proven design. They are also fully automated, requiring minimal operator interaction. Their dual intermeshing rotor design is self-clearing, yielding a uniform Class A product.

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ma -Fli te At Work T her Teamwork and Technology Makes Class A Biosolids Production a Reality More Key Criteria: Compactness and Capital Outlay. As the project progressed, Bowen was directed to fit the dryer into a second-floor room of an existing structure, historically used for dewatering sludge. This directive would solve many problems for American Water--not the least of which was reducing initial capital outlay--but it also presented its own set of challenges. Luckily, the compact footprint of the Therma-Flite IC dryer was ideal for the room. American Waters was at the beginning of a 50-year contract. Cost analysis had to be a part of the planning. Everyone involved in the project was committed to good stewardship of government funds. Controlling construction, and O&M cost was key to the success of this project.

Adaptability and the Science of Sludge. Therma-Flite’s dryer design was impressive on many levels. Indirect heating was the ticket to a quality, saleable, uniform end product. EPA Class A requirements are largely based upon time-and temperature regimes. The PLC controlled process ensured lower operation costs going forward because it required little personnel oversight. In addition, Therma-Flite was able to package and deliver a complete turnkey system. Most notably, ThermaFlite has demonstrated the greatest breadth and flexibility in processing sludge at regional plant installations where many different sludge types being dried. This was important for the American Water project. To explain, the present facility handles chemically-induced, co-mingled sludge but with a biological system coming online by end of 2013, American Water would soon be dealing with biological sludge. Volatile content and F.O.G. would be changing and that could cause wide fluctuations in end product on some systems. The Therma-Flite dryer was the most likely to handle the change while keeping end product consistent.

Bowen Engineering Sums it Up...“Therma-Flite deserves kudos not only for equipment design but for understanding the complexities involved. Their technical team helped us get out in front on the project for American Waters. They supplied budgetary numbers, safety parameters, and they gave us all quite an education in the science of sludge. Their equipment, technological savvy and team-building skills helped us meet the desired performance specifications for a successful project.”

The Therma-Flite IC Series dryer will arrive in August ready to install and should be fully integrated by November. Final permitting for the project should be completed by second quarter of 2013, pending testing to meet specifications set forth by the state of Maryland, which are some of the nation’s toughest.

Therma-Flite’s IC Series Bio-Scru dryers are available in six different standard sizes from 800 lbs per hour water evaporation capacity to 10,000 lbs per hour water evaporation capacity. Larger sizes are available as custom designed units. The system is extremely efficient, has a small footprint and is very competitively priced.

For additional information regarding this project please contact: Therma-Flite Contact: Michael Stone (707) 747-5949

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