Arlington Re-Gen Biosolids Upgrade

Reducing greenhouse gas emissions and advancing sustainability goals.

Arlington Re-Gen Biosolids Upgrade incorporates thermal hydrolysis process (THP)
Arlington, VA
Delivery Method
Arlington County, VA
Year Complete

Project Overview

This progressive design-build Arlington Re-Gen project, totaling approximately $175 million, will upgrade the Arlington County Water Pollution Control Plant’s (WPCP) solids handling facilities and incorporate cutting-edge technology to sustainably transform wastewater to a renewable energy source and Class A biosolids, a nutrient-rich soil amendment. The WPCP currently treats more than 23 million gallons of wastewater each day from residences and businesses.

Work includes the design and construction of the thermal hydrolysis process (THP), pre- and final-dewatering facilities, primary and secondary anaerobic digesters, sludge screening and storage facilities, odor control, biogas treatment systems and steam generation. THP will allow the WPCP to produce Class A biosolids that can be used as fertilizer and the resulting biogas will be captured, treated and used as a renewable energy source.

Sustainability and resiliency are key factors in the design and construction, which positions the project to pursue an Envision Gold verification. The new processes will be net-energy positive and produce more energy in the form of renewable natural gas than will be consumed through operation of the solids handling facilities, reducing the County’s reliance on fossil fuels.



Million Progressive Design-Build Project


Ton/Year Reduction in Greenhouse Gas Emissions


Decrease in Overall Truck Traffic