New sewer plant under construction

Construction on the new sewer plant that is just west of the existing plant is well under way. City engineering technician Keith Henkel said Thursday that the foundation for the building that houses the main tanks is complete and that he expects all the interior walls for those tanks to be poured within the next few weeks. He expects the new sewer plant to be functional by spring 2013. Gridor Construction of Buffalo, Minn., is building the plant, which will cost about $15 million.

City Administrator Brent Hinson said one of the other buildings under construction is the ?headworks? building. Henkel said the foundation and ground floor of that building has been poured. Hinson said the headworks building filters the ?grit? from the waste before it is passed through the other treatment facilities.

?People flush all kinds of crazy things down toilets,? he said.

Henkel said there will be other buildings on the property that are not yet started, such as a building for the offices and the laboratories.

?I?m not sure when they?re going to start that, but that will be last,? Henkel said.

Henkel said the headworks and the tanks are being built first because they connect to the gravity sewer, which is also new.

?There is going to be a transition time when the new plant is up and running and when we shut down the old one,? Henkel said.

The city will continue to use the current lagoon, but it is also building another lagoon west of the new sewer plant. Henkel said the new lagoon will be about four times larger than the existing one. A bulldozer flattened the dirt on the floor of the lagoon Thursday morning, which will eventually have a synthetic liner as a bed.

?This lagoon is for excess storage,? Hinson said. ?When the flow is beyond what the plant can handle, it?s going to come to this lagoon, and it?s going to sit here until the plant is ready to treat it. The plant is actually designed to use the lagoon. By putting this in, you can build the plant a little smaller, believe it or not.?

That said, Hinson noted the new sewer plant will be ?enormous? compared to the current one. He said Washington needs a bigger plant because the current plant is treating more inflow than it was designed to.

?Right now, the biggest problem Washington has is that its plant is supposed to treat 2 million gallons per day and yet, when we have heavy rains, we get 6 million gallons or more,? he said.

Hinson said this excess is due to rainwater infiltration. Instead of entering the storm sewer, the rain finds its way into the sanitary sewer. The city has attempted to remedy this problem by first locating the points of infiltration. In the fall of 2009, the city blew smoke through a portion of its sanitary sewer to see where infiltration was taking place by where the smoke came out. For instance, the city knew infiltration was occurring if smoke rose from down spouts or gutters.

The Department of Natural Resources ordered the city to build a new sewer plant in order to treat the millions of excess flow coming into the sewer plant.

?The City of Washington had to build this. There was no alternative,? Hinson said. ?If we didn?t do it, there was going to be a federal lawsuit, and nobody wanted that. The city might have also had to pay massive fines.?

Hinson said the DNR has the power to prevent the city from connecting any new homes or businesses to its sanitary system if the city is not in compliance with DNR orders.

?That would be devastating,? Hinson said. ?You?re basically saying, ?No growth can occur.??

The Washington City Council learned earlier this year that in order to pay back the loan for the sewer plant and the gravity sewer, the city would need to generate an additional $1 million per year in utility fees. To accomplish this, the council passed an ordinance in July which raised the sewer variable rate and the sewer base fee for residences and businesses. Every resident?s base sewer fee at least doubled because of the ordinance. Every resident?s water bill rose by at least $20 a month and many residents saw increases of anywhere from $30 to $60 per month.