Auto Technology Translated: Rain Sensor Helping to Make Rivers Cleaner

MINNEAPOLIS--June 7, 2011: You might have had the pleasure of driving a luxury car equipped with rain sensing windshield wipers. Recently, Hydreon Corporation has developed a new optical rain sensor that uses the same principles as automotive rain sensors, and is now being used to make wastewater treatment plants more efficient. The Hydreon Optical Rain Gauge is a sensor about the size of a tennis ball. It uses beams of infrared light to sense water hitting the outside surface. Hydreon was involved with the development of the technology for the automotive industry, where cost, reliability, and ruggedness are paramount.

The quality of the water in lakes and rivers has been improving for decades, in part because more sewage is treated before discharge. Still, about half the raw sewage generated in the U.S. never gets treated. One of the reasons for this is that many systems intermingle rainwater runoff and sanitary sewage. In periods of heavy rainfall, the treatment plant cannot handle the amount of mixed water and sewage coming in, and they dump the untreated mixture directly. The problem is compounded because almost no sewage treatment plants have any way of knowing whether what is coming in is mostly rainwater or sewage. Rainfall rate would be a useful input for sewage-treatment control systems. Meteorological rain sensors, however, are generally based on delicate mechanical tipping buckets that require too much periodic maintenance for application in wastewater treatment.

The Hydreon Optical Rain Gauge provides wastewater treatment facilities with reliable information. The device has no moving parts, and the convex surface is self-cleaning, making the device maintenance free. Control systems of wastewater treatment plants can use data provided by the Rain Gauge to keep the level of untreated discharge to a minimum. The rain data also serves as a diagnostic to optimize inflow, outflow, and energy usage. Given that millions of tons of sewage are generated in the U.S. daily, even a small improvement in wastewater treatment efficiency can have an impact in the water quality of rivers and lakes. 

Leading the charge toward sustainable wastewater solutions is Adenus Technologies of Tennessee. Adenus has developed sewage systems that treat and dispose of sewage largely in the same place it is generated. The systems are generally more efficient and lower cost than traditional, highly centralized municipal sewer systems. The Adenus systems "decrease the cost of creating a community that is more environmentally friendly," says Bob Pickney, Chief Technical Officer of Adenus. Adenus is among the first in the wastewater industry to incorporate the Hydreon Rain Gauge. Mr. Pickney reports that the Hydreon Rain Gauge "greatly improves our Quality Assurance / Quality Control program for monitoring wastewater plants."

Because it is descended from the high-volume automotive industry, the cost of the Rain Gauge is low; Hydreon Optical Rain Gauges cost just $99 in single piece quantity. Rain Gauges are also finding applications in building automation, meteorology, irrigation, and a host of other fields. For more information, visit Rain Sensors .