Sacramento County

When most people think of Sacramento County, California they typically conjure up images of the 'Gold Rushä that took place over 150 years ago. Thousands flocked to the region in search of their fortune then and the growth hasnât slowed. Today, over 2.5 million people call Sacramento County home. While most people recognize the importance of a reliable underground infrastructure in a rapidly growing community, few people think about the services required to maintain such a system on a daily basis. That is, with the exception of personnel with the Sacramento Regional County Sanitation District (SRCSD). A commitment to protect public health and keep the Sacramento River clean lies at the heart of SRCSDâs core. Over 2,500 miles of underground pipeline run through the countyâs 994 square mile area transporting an average of 165 million gallons of wastewater on its way to the Sacramento Regional Wastewater Treatment Plant.

Flow monitoring is a proven method used for understanding system-wide flow characteristics under a wide range of conditions. The monitoring of these wastewater flows utilizing accurate flow instrumentation is of utmost importance in both the daily operation of the entire system as well as future system sizing requirements. According to Dave Aebersold, Principal Engineering Technician for SRCSD, 'Many different types of flowmeters are used by the SRCSD. Meters are needed to monitor day-to-day flows as well as to monitor dry and wet weather flows for inflow and infiltration (I&I) metering. Itâs a matter of finding the right tool for the right job.ä

In 2001, the SRCSD had a requirement to purchase flowmeters to monitor some of the countyâs larger flows in various points throughout their collection system. Aebersold adds, 'One of our engineers mentioned that he had read an article in a trade publication about the Marsh-McBirney Flo-Dar meter. Basically from there, Marshâs local representative, Paul Troxell of Seltek, Inc. along with Regional Sales Manager Richard Espy, presented the product to us and set us up for a demo.ä

Within SRCSDâs expansive collection system, many flow monitoring sites include large flows as well as manholes with depths of up to 40 feet. The Flo-Dar Radar Velocity Flowmeter remotely monitors flows with the use of an 'above-the-flowä sensor that simplifies the entire flow monitoring process. Maintenance costs associated with fouled sensors are entirely eliminated utilizing the Flo-Dar meter. Additionally, equipment and manpower costs for confined space entry are significantly reduced as the sensor can be safely removed and reinstalled from street level.

After the successful demonstration of the Flo-Dar meter, an order was placed for two (2) of the portable (battery operated) Flo-Dar meters. Aebersold states, 'The fact that the Flo-Dar sensor is non-intrusive is what pretty much sold the engineers. After the initial installation, access and retrieval of the meter is a key point as well.ä He further comments, 'We are using the permanent sensor mounts for our needs.ä The Flo-Dar sensor can either be mounted with a portable jack-bar type mount or a permanent mount that is quickly affixed to the manhole wall.

Subsequently, an order for ten (10) additional meters was placed within the following year. One of the ten meters ordered included an optional extended range sensor for monitoring flows in manholes up to 18 feet deep. Aebersold adds, 'We have been pleased with the meters and plan to order five (5) more extended range. We also have plans to purchase three (3) of the DC powered Flo-Dar meters for flow control purposes at one of our facilities pump stations. The plant is currently being built and meter installation will be this summer.ä With thirteen (13) Flo-Dar meters hard at work and plans for eight (8) additional meters in the near future, it appears that SRCSD flow monitoring personnel have indeed found the Îright tool for the right jobâ.