Speaking of wastwater treatment plants (pics)

[Cabin Fever]

Below are a couple of photos of a wastewater treatment system that is under construction near us (Emily, Minnesota). The review and approval of this project was one of my jobs at work (State of Minnesota).

This is a "pond" treatment system that consists of three pond cells, each cell is about 3 acres or so in size. What you see is the 40-mil PVC liner. After the liner is placed, 1-foot of sand will placed on top of it for protection from sunlight and then a layer of rock (rip-rap) will be placed on the dike slopes for protection from wave action.

Wastewater is routed thru the pond cells and is then discharged once it is treated. Treatment is via a natural, biological process. The ponds are sized to hold about 6 months of wastewater from a city of about 200 people with no industry. About one-half of the wastewater systems in Minnesota are of this type...mainlyfor smaller cities.

[fordson major]

have seen and pumped biosolids from one of this type of system. good cost effective system!

[Mid Tn Mama]

There is a cheese factory in WI that does this and it is very interesting. Imagine how much more ecologically and financially smart it would be to do this for homes and businesses where possible.

[fishhead]

CF,

Where is this plant?

I'm in Merrifield.

[Cabin Fever]

Emily, MN

About a mile or so west of town, north of CR-1.

[fishhead]

Thanks.

I'm wondering why there isn't a wetland cell and where the discharge goes?

Using wetlands for water treatment is an interest of mine.

[WisJim]

The Cedar Grove Cheese factory in Plain, Wi, uses a bit of a different system I think) that uses a constructed wetland to treat the waste from the cheese factory.
http://www.cedargrovecheese.com/ Click on "Our Environmental Policy" in the list on the left for more info.

[uncle Will in In.]

Kewanna Ind has a similar setup. They use a center pivot irragater to dispatch the treated water. They had to buy another 10 acres of ground after they were using it to be able to absorb the water.

[Cabin Fever]

Wastewater is biologically-treated for an average of six months in these treatment ponds. The effluent from the ponds is further treated by soil in “rapid infiltration basins.” You cannot see the infiltration basins in the photos I posted. The soil treatment is similar to the treatment one gets in their septic leachfield.

We have several constructed wetland treatment systems in Minnesota. Generally, these systems are preceded by wastewater treatment ponds just like the oens in the photos above. The effluent from the ponds is overflows to the wetland. The wetland biologically removes nutrients and further “polishes” the wastewater. The wastewater is then discharged to the soil or a receiving stream. One problem with wetland treatment is the wetland vegetation should be harvested on an annual basis. Without the removal of vegetation, the decomposing plants start putting nutrients and an organic load back into the wastewater.

The following will be of no interest to anyone other than Fishhead: To familiarize you with some of the other wastewater systems in the area, I provide the following list:
Mechanical treatment plants: Brainerd, Aitkin, Crosslake, Pine River
Large municipal drainfield system: Backus, Lakeshore,
Wastewater treatment ponds that discharge to waterbodies: Crosby/Ironton, East Gull Lake, Pillager
Wastewater treatment ponds followed by infiltration basins: Verndale, Emily, Walker
Wastewater treatment ponds followed by spray irrigation: Cass Lake, Pequot Lakes, Nisswa (golf course irrigation), Hackensack (also inf. basins)

Hey Fishhead, since I drive through Merrifield everyday, we should meet at the Wagon Wheel or the Half Moon Saloon for a beer after work sometime.

[fishhead]

Beer? Sounds good to me.

Pick a day next week. I've got a contractor coming to build an artificial stream soon but he hasn't given me a day yet.

[Ramblin Wreck]

They're doing more spray fields in our area now. I'm not sure why they switched to this mode, but it has become more popular.

[FrankTheTank]

Family member works for sewer dept here in LaCrosse. I'll have to see how it works. I know (most if not all) the "solids" get used for agriculture and i'm assuming the "liquids" are treated and dumped into the Mississippi.