South Carolina Utility Adopts Cellular SCADA System
New system allows Marlboro Water Co. to remotely monitor & control pumps
Marlboro Water Co. (MWC), established in 1972, is a small water company nestled in the Pee Dee area of South Carolina. For nearly 40 years, MWC has served the community of Marlboro County and surrounding industrial neighbors. When they were faced with the need to reduce ongoing operating and administrative costs while increasing efficiency, Marlboro Water Co. turned to a SCADA solution that, by far, exceeded their expectations.
Bobby Brock, the general manager for MWC and president of the South Carolina Rural Water Assn., knew that changes needed to be made, but trying to find a solution that could work within his budget, both upfront and in the future, was going to be major challenge.
For more than 35 years, MWC monitored and controlled their water system using dedicated phone lines for pressure switches that controlled the pumps in five groundwater wells. This proved to be a great burden, both on the equipment and on the employees of MWC. Not only were the phone lines expensive and inadequate, but they also failed to provide MWC with the required data they needed in order to operate their water system efficiently.
“We had no way to monitor if the pumps were coming on or going off other than physically being at the treatment plant. Aside from that, there was also no way for us to know in real time if there was a leak in one of our tanks,” said Brock.
These types of problems required field personnel to spend a great amount of time conducting daily inspection visits, which caused unpredictable costs to be incurred. Reliability was also compromised because of the high susceptibility to failure during heavy storms and reporting capabilities were nonexistent.
As the community that MWC serves continued to grow, they began searching for a SCADA system with doubt that they could implement something at a price they could afford.
“We are a small water company with over 2,000 customers. Most of the larger water utilities had SCADA that cost $1 million plus and I knew we could not afford this type of system,” said Brock.
About four years ago, MWC was introduced to Mission Communications, a cellular-based SCADA provider in the water and wastewater industry, during a presentation to the Pee Dee Rural Water Assn. During the presentation, MWC explained the problems they were facing and Mission proposed a solution.
One of the dynamics of the solution was the tank and well control package. It would allow MWC to set and adjust the various pump on/pump off trigger levels resulting in complete and reliable control of their tank levels. It would also give them real-time alarms and access to historical data that could be used for system evaluation.
“I was impressed with what Mission could do to help us and the price was affordable for a small water utility such as MWC,” said Brock.
MWC currently acquires water from five groundwater wells, where it is then pumped to two treatment facilities and treated with chlorine, phosphate and lime for disinfection, corrosion and pH control. The groundwater wells range from 281,000 gal per day (gpd) and 410,000 gpd, on average. The treated water is housed in three elevated storage tanks with capacities ranging from 200,000 to 300,000 gal.
The Mission Communications model M800 combined with the tank and well package proved to be a perfect fit for Marlboro Water Co. Each site is equipped with an RTU that is part of a tank and well package, allowing the water in the storage tanks to be continuously maintained at an optimum level.
“We configured our system, so that our main tank would be designated to control the pumps in three groundwater wells to turn on and off. We set the high and low level boundaries for all of our tanks on our web portal. If the level drops below the minimum value, the pumps turn on; when the level reaches its maximum capacity, the pumps turn off,” said Brock.
The Mission SCADA system provided MWC with the ability to remotely monitor and control their pumps in real-time, access data for system analysis and visibility and receive immediate alarms for less than the cost of the dedicated phone lines. Aside from the cost savings that were incurred by replacing the phone lines, operating and field labor costs also decreased due to reduced inspection visits.
By utilizing cellular-based SCADA and removing phone lines that could be damaged during heavy storms, MWC is now able to operate during all types of weather conditions. By having the ability to adjust settings and access data via smartphones, personnel are now able to access their system while they are away from their desks.
“We monitor and update our system using iPhones; laptops are not needed anymore. If there is a problem at one of the sites, we typically know what it is before we get there. This has made our lives easier and has given us a lot more flexibility,” said Brock.
“I can determine from the tank level graphs if the system is performing at its best and, through data variability graphs, I can detect and locate leaks. This system has allowed us to do so much more than what we intentionally installed it for,” Brock added. “Looking back, I don’t know how we ever operated without it.”