Unique sludge handling techniques

Enhanced sludge holding capacity in the Clearford clarifier may result in over 50% lower overall volume of sewage sludge that requires disposal; sludge accumulation rates follows a "hockey-stick" function, meaning that the sludge initially accumulates at a high rate, but will eventually change to a lower rate. Sludge accumulation rates have been measured to fall from 0.34 L/c/d (litres/capita/day) after 6 months to 0.16 L/c/d after 3 1/2 years. By having a larger volume of sludge holding capacity, Clearford clarifiers allow more time for biodegradation of sludges and for the biological activity in the tank to reach the optimal (lower) rate of sludge generation. More frequent sludge pumping and removal can result in an increase of up to 100% of sludge volume requiring disposal (see the table below). Clearford testing has confirmed that extended holding times in the clarifiers are possible.

By having the primary clarification occur at the source of wastewater generation, it allows the source separation of sludges. Industrial and residential waste sludges are conveniently segregated and achieve a source control measure as reported in the "National Manual of Good Practice for Biosolids" in the United States and Canada's Best Practices series for Biosolids Management Programs. This is in direct contrast to a centralized method of solids collection at a central treatment plant, which combines waste from all sources and will result in a more complex, lower quality and possibly toxic non-residential sludge with potential for adverse environmental and health effects.