Activated-sludge Plant Becomes Denitrification Plant without Adding Tanks
The plant's location along Highway 1 decreed a discrete appearance. At the same time, the state-park setting required that the plant produce a very-high-quality effluent.
To meet these specifications, <%=company%> designed a 0.096-MGD biological treatment plant with aeration, clarification, skimming, surge control, tertiary-filtration and solids dewatering. Equipment would include the company's stainless steel ClarAtor clarifier with the SEQUOX nutrient-removal process, Radial Filter, and DRAIMAD solids-dewatering system.
The rainy, coastal climate had hampered effective sludge dewatering by the plant's old sand drying beds. This, according to Aero-Mod, no longer is a problem for the new 12-bag DRAIMAD system, occupying the area of the former drying beds. The bags' unique material allows water to drain while repelling rainwater.
The rehabilitation also included adding an aerobic digester--originally part of the old plant's clarifier-which is used to further stabilize the sludge.
Most important, the Aero-Mod system design retained the plant's previous footprint. According to Al Velasquez, plant operator, "Another design had the digester tank in a different location. We would have had to hire archeological and cultural consultants about expanding the location."
At the same time, keeping the same footprint allowed the state to invest more into the system, and produce a higher quality effluent than with the old system. "The quality is more consistent," said Velasquez. In fact, since start-up, the plant reportedly has regularly produced effluent with TSS and BOD levels of less than 2.0 mg/L.
The Aero-Mod system also eliminated two RAS pumps, reducing energy expenses and repair work. "Before we spent a lot of time on repairs and had a lot of treatment downtime," said Velasquez, "now we car take care of preventive maintenance."
Following tertiary treatment, the effluent flows to a leach field, so there is no direct discharge. The plant is also able to handle shock loads that often result during rainy winters.
The plant provides treatment for all of the state park's facilities, which include a lodge--with cabins and a restaurant--camp sites and restrooms, and U.S. Forest Service offices, dorms, and administrative offices.
Aero-Mod, part of the Biological Wastewater Systems Division of Waterlink, specializes in custom-designed biological wastewater treatment solutions represented by hundreds of installations worldwide. The company also offers several standalone products for solids dewatering.
Waterlink is an international provider of integrated water-purification and wastewater-treatment solutions for industrial and municipal water and wastewater applications. Its executive offices are in Canton, OH, and its European operations are in Nynashamn, Sweden.
Aero-Mod, 7927 U.S. Highway 24, Manhattan, Kansas 66502. Tel: 785-537-4995 Fax; 785- 537-0813; E-mail: aeromod@waterlink.com.
Contact: Darci McLain, .Hemdon communications coordinator. Tel: 785-537-4995; E-mail: Aero-Mod@watedink. com