Our Aqua Virginia team recently completed an innovative wastewater treatment plant upgrade to improve service, protect local waterways, and operate more efficiently for the Lake Monticello community just outside Charlottesville.
Aqua had two overarching goals. We wanted to improve the quality of the plant’s treated wastewater, which is discharged into the stringently regulated Chesapeake Bay watershed. We also wanted to minimize future rate increases for customers by reducing operating expenses and deferring the need for a major plant overhaul, which would cost much more.
Consulting the Expert
We spoke to Aqua’s operations manager Dan Hingley, who engineered the project and oversaw construction. “While upgrades to water systems typically result in obvious improvements for customers — like better pressure or more reliable service — improvements to a wastewater system often go unnoticed,” said Hingley. “In fact, many of us don’t even think about our wastewater after it goes down the drain or is flushed away. Meanwhile, a lot of effort goes into collecting, transporting, and cleaning wastewater, and customers rely on us to protect the environment and their local waterways. This project demonstrates how we do that.”
The treatment concepts we used aren’t new, but the way we applied them required creativity and innovation to achieve goals at a lower cost. Making wise decisions about which treatment process to use and which types of equipment to install alleviated the total capital cost of the project.
Aqua reconfigured the layout of the wastewater plant and added some new aeration system controls to optimize treatment. The team used baffle walls to create new zones within the existing tanks. These baffles control water flow, prolong the amount of time the wastewater spends in treatment tanks, and separate a single tank into multiple treatment stages. While the previous process was a single tank that was continuously aerated, the modified process added new zones that weren’t aerated to allow specific bacteria to eat organic matter in the untreated wastewater, which removes a nutrient called nitrogen.
In these new unaerated zones, Aqua had to install a mixing system since it was no longer being provided by the diffused aeration system. Aqua collaborated with a neighboring utility to design and build mixers that connect to the existing air supply system and release large air bubbles, rather than the smaller diffused air bubbles, to induce mixing. This solution costs less to create and costs less to operate than installing mechanical mixers.
“Aqua’s top priority is to deliver safe, reliable drinking water and wastewater services to our customers,” noted Aqua Virginia President John Aulbach. “These upgrades in Lake Monticello will strengthen our infrastructure, improve service, and help protect the environment.”
At its 2019 Summit, the National Association for Water Companies awarded Aqua a Management Innovation award for this project completed at the Lake Monticello wastewater treatment plant. The award recognizes a utility that has implemented groundbreaking and industry-changing ideas.
Aqua provides water and wastewater service to about 80,000 people in 37 counties across Virginia.
Keep an eye on our blog to go behind the scenes of more of our infrastructure improvement projects throughout 2020!