Where does all the stormwater go?Published 7:00pm Thursday, November 7, 2013
Editor’s note: This is the first installment of a regular series that aims to explore processes and answer questions in detail.
On an average rainy afternoon in Alexander City, most may see the rainwater go down a sewage drain and not think twice about it. But there is a process when it comes to processing stormwater.
City engineer Gerard Brewer said it is important to keep stormwater out of the city’s sanitary sewer system for several reasons.
“One reason is that you don’t want to have to treat it,” Brewer said. “You have chemicals you use per gallon of waste water you get, so when you get the stormwater you’re treating water that doesn’t need to be treated. Toilets and things like that, that waste water does need to be treated, but stormwater doesn’t need to be treated, so it’s costing you money.”
Brewer added that stormwater causes damage to the system in the form of over-pressurization of pipes, manholes and other parts of sewer infrastructure because the system is not designed to carry that much water.
But most importantly, Brewer said stormwater can cause a problem in the form of sanitary sewer overflows.
“The last thing, and probably the most detrimental thing, is sanitary sewer overflows,” Brewer said. “It’s not a pretty thing. You get a section of manholes where sewer is flowing downhill, and if there’s a lot of water getting in at the top, then a lot of water can up out of the manholes downhill. Along with it – even if it’s 90 percent stormwater – can come bathroom waste. That’s a bad situation.”
Brewer said in order to keep stormwater out of the system is by constantly working to make sure the sewer system is up to standards.
“There’s no way necessarily to keep it out, but the way you try is through a real aggressive maintenance program in which you routinely inspect the sewers and make repairs where you think water is getting in,” Brewer said. “To get it out is what we’re working on now. You have to clean and inspect the system through CCTV (closed-circuit television).”
Brewer said the public works is given $800,000 a year from the city in order to assess the system and inspect and clean some 150 miles of sewer infrastructure in Alexander City.
Brewer said the process to aggressively assess the system began in 2010, and the department has inspected and cleaned about 65 percent of the system.
Soon, the department will contract out the repairs needed for the city’s system.
“We have identified thousands of repairs. What we’ll do now is we’ve got repairs together sitting in work orders that we’re going to put out to contractors to repair,” Brewer said. “Some contractor will bid on a job, they’ll come here and probably do about a half-million dollars worth of repairs this year. That’s what we’re trying to get lined up to do.”