Sunday, September 7, 2014

Clean Water?

WELLSVILLE:  Flush a toilet, wash a dish, enjoy your shower and forget what goes down the drain. That’s what many do every day while a crew of 3 waits “downhill” ready to turn our nasty sewage into river-ready water.
            This past week I stood on some sturdy grates looking down on Wellsville’s daily 1.4 million gallons of sewage as it rushed into the Wellsville Sewer Department
             I toured the facility with Joanne Allen and Barry Miller of Concerned Citizens of Allegany County while Michael Smith and Brad Mattison explained the sewage treatment processes that relieves Wellsville’s sewage of some of our daily muck.

            We started at the headworks, the unit where water from about 2400 users enters the system. This is the place plagued by baby wipes and the occasional diaper. The water passes through a grinder and a screen but things like baby wipes don’t grind well and can block the screen so sometimes someone has to pull out what looks like stiff, white fiber.

            The water that rushed under our feet was raw sewage at its worst but it didn’t smell much. Smith said that’s because there is a lot of water in the system just now. He said that waste water comes from homes, stores and businesses but there is also water that seeps into the system through broken pipes. Pipes, he said, always leak somewhere.
            This water is only domestic sewage. Storm water doesn’t mix in. The Village worked aggressively in the 70s, in response to Nixon’s Clean Water Act, to separate sewage and storm water. At the time there was grant money to upgrade systems and Wellsville took advantage of that money to separate the two water streams.
            After the sewer water passes through the grinder and the screen it goes into an aerated grit chamber where air helps to suspend organics (that’s the polite word) and let grit like sand, coffee grounds, egg shells to settle. There’s a device over the chamber to scoop out the particulate matter that settles. These solids are eventually sent to the county landfill.
            The sewage flows through underground pipes, across the driveway, to the primary settling tanks. Two of these tanks were built in 1937 and the third in 1997. They are all rectangular, concrete ponds with gooey, yellow grease floating in the corners and, while the water is 10 feet deep, there is almost no visibility.  
            The tanks have metal bars across at regular intervals. The bars are mechanical scrapers that travel along the bottom of the tank pushing sludge (another polite term representing various components) toward a hopper. The bars move a circular route up the side, across the top and then down again to scrape the bottom.  Pretty much as soon as they enter the dense water, they disappear.
            These tanks are nearly 80 years old and they look solid. Several parts of the system are that old but it all seems well cared for.
            At the settling tanks, another waste stream is introduced and that’s the leachate from the Hyland Landfill.
            Leachate is water that has dissolved and carried away a substance. Rain that passes over orange peels and manure in a compost bin is leachate as is water than passes over used batteries, gunk from a dirty garage floor, home cleaning or garden chemicals and rotting food or whatever else might end up in a landfill.
            The leachate from the Hyland Landfill matters to members of CCAC because of drill cuttings and waste from hydrofracking wells. The wells are fracked with processed water which can have any of 500 chemicals and the shale formations are known repositories of water-soluble radon.
            30,000 to 40,000 gallons of leachate enters the settling tanks every day but Smith says it’s watered down by all the domestic waste. The staff at the Sewer Department does not measure radiation (alpha waves) and is unconcerned about any levels of radioactivity that workers are exposed to.
            Likewise they do not measure or remove any medications, hormones or other drugs that the people living in those 2400 houses might be pouring down the drain or passing through their bodies. Smith said that some people see those substances as “forever” in water.
            So, at the tanks, the sludge moves off to anaerobic digesters and the water goes to a recirculating building where pumps send it to a trickling filter. This 120 foot diameter tub has a 6 foot deep bed of chunks of limestone. There are 4 perforated arms attached at the center. As the arms turn, water sprays over the limestone and trickles through the stone to eventual aeration and release into the Genesee.
            There is a second 120 foot wide tank with smaller stones that water passes through in the summer. Called a polishing filter, this tank freezes in the winter hence the summer-only use.
            The sludge in digesters continues to break down via anaerobic bacteria. Sludge is added and removed daily but what we saw go in will stay there about 25-30 days. Bacteria are free, but they can’t be rushed.
            Bacteria give off methane as they break down organics and while the methane and volatile chemicals escape into the air freely over the settling tanks, the sludge in the digesters gives off enough methane to make capturing the gas worthwhile. That methane is used to heat the digesters to keep them at a temperature that keeps bacteria working.
            When the sludge is removed it is either put in sheds to air dry or it is squeezed dry in a dewatering press, a machine that looks rather like a printing press. The sludge is pressed between powerful rollers to force out the water leaving behind solids that can be sent to the Allegany County Landfill while the water runs through treatment system again. 
            Every step of the way bacteria works to break down contaminants. Before the water is released into the Genesee, ferric chloride is added so it will bind to phosphorus which is not wanted in rivers. In the 70s water was treated with chlorine but that practice is now seen as harmful.      
             There are some daily, weekly and monthly chemical tests performed on the water to be certain that the facility is cleaning the sewage properly.
            There was a lot of information covered by Smith and Mattison who were generous with their time.  Joanne Allen said that when she saw the amount of equipment and the processes involved, it made her feel better about paying her sewer bill.
            Smith said that people who want to help the Sewer Department run smoothly, should stop flushing baby wipes and dumping grease down their drains. Both create problems, one by jamming up the shredders and the screens and the other by gumming things up.
            The other practice he strongly suggested was to compost food waste. It’s better for each of us to create usable compost than it is to send more sludge to the landfill.


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