How Anglian Water and other utilities are controlling algae growth

American Water is the largest and most geographically diverse US public water and wastewater utility. The company employs more than 7,000 people to provide drinking water, wastewater and other related services to more than 15 million people across 46 states.

American Water needed to control toxic algae and cyanobacteria present in the Canoe Brook Water Treatment Plant in Short Hills, New Jersey. Additionally, it was necessary to eliminate foul odour and taste issues.

“The reservoir was shallow and eutrophic due to moderate-high levels of nutrients, leading to seasonally excessing algal blooms.”

The reservoir was shallow and eutrophic due to moderate-high levels of nutrients. This combination of factors led to seasonally excessive algal blooms, as well as impaired filter runs.

The first step towards determining whether ultrasound technology would solve the challenges was to conduct extensive research. This was done by installing LG Sonic’s MPC-Buoy systems within the reservoir and monitoring key water parameters.

“Extensive testing conducted during 2014 showed that the buoys had a significant impact on the algae, allowing the plant to reduce chemical consumption by more than 20 per cent, and reducing the concentration of undesirable taste and odour causing compounds in the treated water delivered to customers,” said Dr Orren Schneider, manager of water technology, American Water.

In the past, the reservoir had been treated with copper sulfate or Cutrine-Plus (copper ethanolamine complex); hence, the secondary objective of the project was to decrease chemical dosing. It was indeed possible to entirely eliminate algaecide use in the raw water reservoir.

Compared to the same time period in 2013, results showed:

• Improved DAF effluent turbidity (37 per cent lower)
• Lower combined filter effluent turbidity (19 per cent lower)
• Longer filter runs (127 per cent better)
• Higher unit filter run volumes (83 per cent higher)

Overall, the use of the MPC-Buoys resulted in OPEX savings of approximately $87,800 (based on projected chemical savings compared to 2013, elimination of copper treatment for the reservoir, and reduced monitoring costs).

Since the first installation in New Jersey, American Water has deployed ultrasonic systems in other water reservoirs, including Pennsylvania, Iowa and Maryland.