Weathering the Storm: Equipping Wastewater Treatment Plants with Flood-Proof Actuators

Author: Steve Poling

As we approach the 6th anniversary of Hurricane Sandy and just passing the 1st anniversary of Hurricane Harvey, the anxieties of facing another superstorm weighs on the minds of every coastal wastewater treatment operator. And with Hurricane Florence approaching the U.S. Carolinas, this string of major storms continues. Are we prepared?

By design, most wastewater facilities are in low-lying areas near the bodies of water into which they discharge their final effluent and allows for gravity fed collection systems. Some systems also include pump stations where head differential is insufficient for flow. Thus, these facilities are prone to flooding from severe storm surge and high tides.

Additionally, most older sewer systems use combined sewer collection systems. This means that storm drains are combined with sanitary sewer lines which, in heavy rain, can cause a combined sewer overflow (CSO) event. These are characterized by a potential high flow or surge of water following a heavy downpour that inundates the facility for a shorter time. In either situation, the facility can be overwhelmed, and processes can be disrupted, throwing off the balance of the treatment processes and can lead to raw sewage spills into the environment.

After experiencing costly failure issues with existing hydraulic actuators, a large Northeast municipal sewer authority realized they needed a more reliable solution to help them weather the next storm and asked the experts at Emerson for help.

Emerson's EIM Aquanaught submersible electric valve actuatorAs a result, Emerson created the EIM Aquanaught, a submersible electric actuator with a two-piece assembly built to operate at up to 150 ft of dirty water for seven days with the control cover open and controls exposed.

Its waterproof enclosure and hermetically sealed connections ensure uninterrupted plant operation during flooding conditions, allowing operators to remain in control from a safe remote location even when the actuator is completely submerged.

These actuators have been installed for more than 10 years and endured some of the East Coast’s most notorious hurricane events, including Hurricane Irene and Superstorm Sandy. In a follow up with chief operators, the Emerson team discovered the Aquanaught allowed plant operators to plan for and react to these unavoidable weather events instead of waiting for something to fail. This saved the facility the expense of starting up additional plant throughput resources until it was absolutely necessary. Additionally, the plant could get their process under control faster and prevented spilling raw sewage into the environment.

The Environmental Protection Agency (EPA) estimates that 34 billion gallons of wastewater are processed in the USA every day. During events like Hurricanes Sandy, Irma and Harvey, billions of gallons of untreated sewer overflowed into impacted communities, posing significant health and environmental risks to the affected areas. With some experts predicting that flooding is expected to worsen as climate change progresses, the need for more reliable actuators becomes critical for these facilities.

To learn more about the EIM Aquanaught, visit Emerson’s booth #8121 at WEFTEC October 1-3, in New Orleans, Louisiana.

Steve Poling is Northeast Regional Sales Manager for Emerson Automation Solutions’ Actuation Technologies business.

Posted Wednesday, September 12th, 2018 under Actuator, Water & Wastewater.