Archbald Treatment Plant Solids Handling Improvements

Location: Archbald Borough

Description:

This project modernized aging sludge thickening and dewatering equipment, improving both efficiency and reliability in the solids handling process at the LRBSA treatment facilities.

Sludge Thickening: The plant’s original dissolved air flotation thickener, installed around 1970, was replaced with a modern gravity belt thickener. This new system provides a higher solids capture rate, producing more concentrated solids and reducing the volume of sludge that needs processing, ultimately lowering operating costs.

Sludge Dewatering: Previously, the Archbald plant used a belt filter press from 1991 to remove water from treated sludge. This was replaced by a high-performance centrifuge that spins sludge at high speeds, separating water from solids—similar to a washing machine’s spin cycle. The new centrifuge produces drier biosolids, reducing disposal weight and lowering costs for the LRBSA and its ratepayers.

Aerobic Digestion Improvements: Waste sludge is first treated in aerobic digestion tanks, where air is bubbled through to support biological activity that breaks down organic material. The system of pipes and air diffusers in these tanks was upgraded to improve mixing and enhance performance.

In addition to these key upgrades, supporting systems like polymer feed systems (chemicals used for sludge thickening and dewatering), sludge pumping equipment, and electrical controls were also replaced and improved.

This project was primarily funded by a low-interest loan from the Pennsylvania Infrastructure Investment Authority (PENNVEST).

Completed: August 2018

Construction Cost: $2,908,960