The company that developed the anaerobic digester project at the Altoona Water Authority’s Westerly Sewer Treatment Plant several years ago recently paid the authority $551,000 to make up for a shortfall in operational income from the digester for 2025 — a shortfall that reflects the firm’s difficulties in obtaining sufficient high-strength waste from customers for the digester to process.

Energy Systems Group took on the project as part of a state energy conservation initiative, with a guarantee that for 20 years, participants like the authority would at least break even on digester operations — although there are other energy-saving elements to the authority contract.

Last year was the second year of the 20-year agreement, and the second time ESG covered a shortfall, having paid the authority $479,000 for 2024.

It’s likely there will be a shortfall again for 2026, for which the income target is $681,000, according to Brad Kelly, the authority’s sewer operations director.

Still, the income this year is running ahead of last year’s pace, Kelly said.

It’s somewhat disappointing that ESG is having such trouble securing enough high-strength waste to meet the program goals, according to Kelly.

But ESG appears to be “striving,” with meetings every two weeks to discuss potential customers, he said.

The company initially focused on obtaining product locally, but it has come from as far away as Virginia, and the company has been making inquiries in New York, officials said.

But the farther the product has to travel, the greater the transportation cost.

One potential means of cutting down transportation costs for suppliers of high strength waste would be delivery to the Westerly plant by rail — and adding a rail line to the plant has been at least discussed, officials said.

Other complicating factors in ESG obtaining enough high strength waste are restrictions on metals in the material the authority can accept in the waste it processes, because the material the authority ultimately produces at Westerly is Class A biosolid marketed for general distribution as NutrAWAste.

Authority operators also need to ensure the waste they accept is compatible with digester operations.

There are also competing facilities that can take high strength waste from potential authority customers.

High-strength waste includes grease from restaurant grease traps and discarded material from food processing plants, according to Kelly.

The authority has been able periodically to generate enough methane with the digester to run the boiler for the digester itself, Kelly said.

But the digester has not generated enough methane to run the dryer the authority uses to heat its Class B biosolid cake such that it dries sufficiently to be classified as Class A.

The authority is working with a local university on a possible study of the effectiveness of NutrAWAste for crops, according to Kelly.

Mirror Staff Writer William Kibler is at 814-949-7038.