Preliminary audit predicts revenue for AWA digester

The company that recently began a preliminary energy savings audit of the Altoona Water Authority’s Easterly Sewer Treat­ment Plant has found the authority should be able to obtain enough high strength food waste to warrant the construction of an anaerobic digester.

Energy System Group of Lin­th­i­cum Heights, Md., estimates that a digester could generate $2 million per year in savings or additional revenue at a cost of $1.75 million — including debt service — for net annual earnings of $250,000.

The revenues and costs are based on a conservative inflow of 40,000 gallons a day of food industry waste, but there would probably be 90,000 gallons available if the authority sought it aggressively — with a proportionally bigger earnings potential, according to ESG Senior Business Develop­ment Manager Larry Doyle, who spoke to the authority last week.

ESG expects to finish its preliminary audit in late February, after which the authority would need to decide whether to order a 10-month investment grade audit, at which point it would be committed to either pay for that more detailed audit or ultimately proceed with a digester project — the cost of which would include the price of the second audit.

Typically, an investment grade audit costs about $500,000, or 4 percent of the cost of the digester project, Doyle said.