Smarter Sewers: SCADA

We can all assume that when Mark Twain wrote “Cape Girardeau is situated on a hillside, and makes a handsome appearance” that he wasn’t thinking about wastewater. The hills in Cape Girardeau are handsome. They also make for a challenging bike ride. Paired with gravity, those same hills also help sewage and stormwater flow away from homes and businesses.

Smarter-Sewers-SCADA-MapWhere gravity can’t do the work, the City uses pump stations to push the wastewater uphill to continue its journey to our current treatment facility and to the new one in 2014. Cape Girardeau has 31 pump stations. Sounds like a lot, but Stormwater Program Coordinator Stan Polivick, who spent 20 years as a city engineer in Louisiana, has worked in communities our size with triple that number.

“The topography in Cape Girardeau helps the sewer system,” said Polivick. “There is a line along Lexington to Scivally Park, we have a pump near Broadway-Kingshighway and from there it flows down to the plant. That is a long way to flow by gravity.”

The City maintains 225 miles of sewer lines and 200 miles of stormwater facilities. For perspective, that’s a trip from Cape Girardeau to Wisconsin via Chicago. The sewers carry 6.5 million gallons of wastewater on a typical day. That’s about 10 Olympic-sized swimming pools. In the end, stormwater dumps directly into the river. Wastewater is treated before it reaches the river.

Maintaining the infrastructure is a huge undertaking. In addition to 13 wastewater treatment personnel, the City employs 17 people to maintain the sewer and stormwater system. Pipes break. Creeks flood. Construction companies need to tap-in or reroute. The business of pipe maintenance will never go away.

Polivick-SCADABut, the business is getting smarter through data collection. Several years ago, the City installed Supervisory Control and Data Acquisition (SCADA) systems to monitor pumps and water levels throughout the City. They upgraded a few components in 2009, and back in June 2013, the Council approved a $2.5 million upgrade to the system to be funded by revenue from utility bills and part of the Wastewater Treatment Facility funding.

“One of the great benefits of a SCADA system is data collection and storage,” said Polivick. “It helps us analyze the performance of the sanitary sewer.”

Benefits of SCADA and the new upgrade include:

  • Helps to reduce water pollution
  • Faster response: diagnosis can begin as soon as the problem is reported. Currently, the Public Works Department has to send someone physically out to the location to begin reviewing the problem.
  • Move monitoring operations from the soon to be closed wastewater treatment facility to both the new facility and Public Works Department headquarters.
  • Set alarm conditions to dispatch maintenance crews when a small problem is indicated, well before a big problem is reported by a resident.
  • New system will automatically tabulate when the pumps are on and off – recording switch times and run duration. Public Works engineers can analyze this data to improve routine maintenance.
  • Better understand the impact of rain events.
  • Monitor components 24/7 to refurbish and replace as necessary, before something breaks or fails.
  • Reduce man hours spent checking pumps.
  • New cabinets will have Arc Armor – separating power and data transmission which is safer for employees than what we have now.
  • Improves the quality of our permit applications with the State of Missouri Department of Natural Resources for both our storm and waste water operations.

When SCADA fails, things can get ugly fast. In one incident downtown, workers happened to notice a sewer pump well within an inch of overflowing into the street. With upgraded SCADA, Public Works staff would know well in advance that something needed fixing. In this case, we nearly had sewage flowing in the streets of downtown. Nearly. Luckily, City workers were there, noticed the problem and were able to fix it promptly.

From 2009 through 2012, the City had 15 instances of sewer overflows. Statistically speaking, comparing to other cities, that’s “OK.” To the people that lived near-by and noticed the overflow, that is disgusting and unacceptable. City staff agrees. That’s why it is so important to monitor our infrastructure and fix small things before they become really big, really gross, and really expensive problems.

SCADA is also an important development tool. When a big project happens in town, contractors need to connect to the sewer. During the work, the flow through the pipe must be rerouted or stalled. You can’t just turn off the sewer service in Cape Girardeau. It takes a few engineers many more hours to find that window of opportunity for contractors. For example, when the casino was built, Polivick and then wastewater coordinator Jim Baylor, had to do extensive manual calculations. With more SCADA data at their fingertips, Polivick and our other engineers can find more options for contractors and quickly assess our capability to coordinate the connections of new businesses and developments.

Much of the new Wastewater Treatment Facility SCADA will be hardwired in the facility. Today, much of the SCADA monitoring occurs by radio. Increasingly more distance monitoring and control will be carried by fiber lines. Fiber lines installed as part of the 2010 surface-to-well fresh water project will be used to carry signals for the storm and wastewater.