Eyes On Flow

SmartCover monitors provide real-time alerts to potential overflows for Leucadia Wastewater District
Eyes On Flow
This chart shows the sewage level in the manhole that is monitored by a SmartCover unit for a 30-day period. The graphical pattern (in blue) shows the normal diurnal flow pattern while the dotted red line above is the alarm setpoint that the Leucadia Wastewater District established to alert its standby duty operator. A “high level” alarm would indicate a sewer stoppage and allow the operator to respond and correct this “abnormally high sewage level” before it resulted in

Interested in Rehab/Relining?

Get Rehab/Relining articles, news and videos right in your inbox! Sign up now.

Rehab/Relining + Get Alerts

The general public and regulatory agencies have grown more sensitive to sanitary sewer spills. In states like California, where sewer system management plans (SSMPs) have become the rule and third-party lawsuits have become more common, spill frequency and volume have been measurably reduced.

The reasons include enhanced maintenance, spill-response training, and greater general awareness of the problem among wastewater agencies. Some agencies, including the Leucadia Wastewater District in Carlsbad, Calif., have gone further, adopting formal operation and maintenance programs, publishing design and performance provisions, updating overflow response plans, and developing capacity assurance plans that include monitoring and measurements — elements specified by the U.S. EPA’s proposed Capacity, Management, Operations, and Maintenance (CMOM) program.

Leucadia’s efforts also include use of technology, including SmartCover monitoring and alarm systems that detect potential spills in locations such as known trouble spots on the collection system and pipes in difficult-to-access easement areas. The devices are helping the district prevent spills, reduce easement inspection frequency and document sewer performance history.

 

Easy problems first

Like most agencies implementing new SSMPs, Leucadia addressed the easiest sewer problems first, leaving more challenging and costly work ahead. To sustain its Internet-accessible compliance record, the district also conducted an external audit of its performance and adherence to the SSMP to identify areas for improvement.

That effort revealed two areas of concern: Trouble spots (especially where overflows had occurred) and off-road easement areas difficult to access because of canyon topography, protected biological resources and floodplains. Furthermore, large-diameter pipes, surcharge flows and long distances between access points affect the district’s ability to clean and inspect parts of the collection system.

The district deploys easement inspectors to monitor assets in remote areas.

The inspections mean sending an employee (or a team of employees using the buddy system) into canyons and other unpaved areas to locate manholes, inspect the manholes for deterioration or vandalism, and observe the flow for short periods.

However, these inspections involve hazards that include encounters with snakes, poison ivy and wild animals, along with the chance of injury during foot travel on rough terrain. Thus there were risks to offset the benefits of putting eyes on a given manhole for five minutes per year or per quarter.

 

Automating inspections

In seeking an alternative to labor-intensive inspections and a way to monitor trouble spots more closely, the district installed SmartCover monitoring and alarm systems from Hadronex. The devices, attached below manhole covers, continuously monitor water levels in the sewers and provide user-defined alarm notifications to impending overflow events and to intrusions by unauthorized parties.

The battery-operated units install in a few minutes. Batteries typically last one year. The devices provide two-way wireless communication, allowing the district to interrogate them from anywhere. Data is downloadable for insertion into spreadsheets. Alarms are sent directly to specified district personnel for timely response.

The devices can be easily maintained or traded out by inspection personnel. Thus they provide continuous real-time information for the same level of effort as periodic inspections. Additionally, data from the monitors has given the district an improved picture of sewer lines’ capacity and dynamic performance over longer periods than previously available.

Analysis of the data has allowed the district to target capital improvements more effectively and gain the benefit of each asset’s full useful life. Managers and regulators also appreciate the more detailed data available during spill investigations.

Finally, the alarm function demonstrates the district’s commitment to proactive spill prevention and limits risk exposure in less-traveled and more environmentally sensitive service areas. By installing several SmartCover units and adding more each year, the district has achieved efficiencies in easement inspection. F

 

About the Authors

Leo Schempp is former field services manager and Jeff Stecker is field services superintendent with Leucadia Wastewater District, based in Carlsbad, Calif. Both hold California Water Environment Association Collection System Operator IV certification.



Discussion

Comments on this site are submitted by users and are not endorsed by nor do they reflect the views or opinions of COLE Publishing, Inc. Comments are moderated before being posted.