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| Treatment plant tour Part 2 |
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| The Bear Creek dilemma
A river divides them: A series |
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By Russell Bassett
City of Molalla Public Works Director Dean Madison looks over the side of the railing over Bear Creek, which runs in front of the Molalla Wastewater Plant.
“I don’t care what people say, how are you going to discharge into that,” Madison said.
He acknowledges that it is a summer day and Bear Creek is used only for winter-time discharge, but notes “there have been days in the winter when it has been almost that bad.”
Both Department of Environmental Quality and city staff officials claim that is why the city of Molalla’s winter discharge point in its current permit is set to move from Bear Creek to the Molalla River.
Opponents to the city’s plan are fighting the change, and have put an initiative on the September ballot that would amend the city’s charter and prohibit discharge of sewage — treated or untreated — into the Molalla River.
Opponents claim that the city’s plan is ineffective and that there are other alternatives that would allow the city to continue discharge into Bear Creek (a deeper look at opponents claims will be examined later in the series).
Madison disagrees, and says Molalla has a good plan, which puts out some of the cleanest effluent in the state.
Where it goes in the winter
The treatment for winter discharge alters slightly from summer discharge and is monitored differently.
After going through perforated plates, irritation basin, lagoons and DAF, winter discharge would then pass through two mixed media filters.
Madison explained that a mixed media filter is various layers of rocks, from big to little with coal on top.
“You see them in a water treatment plant,” plant operator Otis Phillips said. “... When it comes through the filters it’s just spotless.”
From there, it’s ready for winter discharge. Factors that are weighed in discharge include Total Suspended Solids (TSS), Biochemical Oxygen Demand (BOD), e. coli, ammonia levels and chlorine, among others.
The numbers most commonly referred to in discharge is the BOD/TSS levels. Molalla’s permit ratio is for a 10/10, which means 10 parts per million and BOD or 10 parts million total suspended solids.
Phillips points out that the plant averages about a 4/4, which it has to meet in order to meet the other part of the discharge equation — the dilution factor, or the flow of the water body that the effluent is being discharged into.
“If we get a 10/10, it would blow dilution factor every day of the week,” he said. “We put out a 4/4, so we’re beating our permit. If we didn’t put it out that clean, we would have a lot of problems. We couldn’t put out any water.”
“If you look around, I don’t know of many plants making a 4/4 (ratio),” Madison said.
On its way to the Molalla river, the effluent will go through what is called cascade aeration.
“That adds oxygen to it so that you have a high BOD when it goes into the river,” Madison said. “DEQ’s original concept was to put air compressors to put air back into it, and we came up with this.”
It’s a matter of flow
The wording on the Sept. 19 ballot will read to the effect on whether the city charter can be amended so that no wastewater, treated or untreated, can be discharged into the Molalla River.
If voters pass that, opponents to the city of Molalla’s Wastewater Facilities Plan would like an alternative that would continue winter discharge into Bear Creek.
The city’s current plan would discharge into the Molalla River during high flows. The city would start discharging into the Molalla River this winter.
Opponents argue if the city fixed a leaky collection system that forces the city to process more influent through its plant via infiltration, as well as find a cost-effective method of secondary treatment, that discharge into Bear Creek could continue and could even rehabilitate the stream.
“Why compound one problem by making another problem?” Connie Derry asked. “Since we’ve already used Bear Creek — I don’t think it’s right that we’ve destroyed a stream — but why not avoid going into the Molalla River and use this as the catalyst to clean up Bear Creek and do it right.”
Phillips notes it not that easy.
“Half the problem with Bear Creek is that it is just a seasonal creek,” he said. “Come May, it starts drying up, and you just can’t put water out there. The biggest problem is having a place to discharge. You could build the best plant in the world, but you still have to have a place to discharge to.”
Future upgrades
Opponents also argue that the city is going to spend money on upcoming upgrades for the plant in the future, so that the city’s argument that a new alterative is going to cost taxpayers money is misleading.
“The city is complaining a lot about costs, and they say its going to cost $30 million,” Attorney Chris Winter said. “Well they already plan on spending $30 million, so what we’re really talking about is how best to spend that money.”
Madison countered, saying “I’m not going to predict what is going to happen over the next 20 years. ... Sewer plans are ongoing and change all of the time, and as growth occurs, there will be more development and further changes to this plant. And they will all cost money, but every one of them will have a discharge of some kind. Where are you going to go for winter?”
He did note what the proposed plans are.
“What we’re doing now is called phase one, and that’s the discharge into the river and finishing the irrigation system on Coleman’s,” he said. “Phase two is another DAF and four more filters. And beyond that, there are plans by 2014 or 2015 for another plant upgrade. One of the things that we will be looking at at that time is converting one of the ponds to activated sludge. That will be a decision left for someone other than me.” |
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