Published October 2007

Sensor Detects Alarming Sewage Levels

By Ken Wysocky (page 62)

The threat of sewage overflows — and resulting in fines, cleanup costs and bad publicity — keep wastewater utility managers up at night.

The threat of sewage overflows — and resulting in fines, cleanup costs and bad publicity — keep wastewater utility managers up at night. The SmartCover early warning detection system from Hadronex LLC attempts to prevent those bouts of insomnia.

The 4-pound SmartCover sensor (2 by 6 by 4 inches) mounts under a manhole cover with an industrial magnet. An acoustical sensor hangs from the unit and continually monitors and records the water level and temperature. The sensor’s range is 3 to 80 inches, but a 20-foot-range sensor is available.

“It’s like a sonar,” explains Tim DeMarco, sales and marketing manager. “Every six minutes it sends down an ultrasonic wave that bounces back up, allowing the sensor to determine the water level. The sensor never touches the water.”

If the water depth exceeds a predetermined level, a wireless alarm immediately notifies the utility’s computer control center and sends alarm signals to key employees’ cell phones and pagers. Alerts are triggered when the voltage runs low in the sensor battery.

The SmartCover also monitors the position of a manhole cover. Any unauthorized intrusion sets off an alarm. The sensor can be turned off to allow authorized maintenance.

“Some of our customers have caught sewer system intruders, thanks to SmartCover,” DeMarco observes.

Installation takes 30 to 60 minutes and requires no confined-space entry. Workers can either remove a manhole cover and install the sensor onsite, or install it on a cover in a utility yard, then take it to the site and substitute it for an existing cover.

“You don’t need this device on every manhole cover,” DeMarco notes. “Every sanitary sewer system has hot spots — areas that are prone to sewage spills. Typically, we find that two to five percent of a system’s manhole covers require this device.”

SmartCover users can access data captured by the sensor on a secure, password-protected web site. There, they can download data — water levels, temperatures and alarm/alert history — on a spreadsheet without any special software. For information: 760/291-1980; www.mysmartcover.com.