Bioswale stormwater mediation before returning to the river.
Editor’s note: Part II of a two-part series.
Besides having a hand in securing Cottage Grove’s first “All America City” designation in 1968, the wastewater treatment plant (WWTP) has been steadily evolving as the town’s population has grown. The facility was expanded and modified in 1984 through an EPA Construction Grant and upgraded in 2006.
Its design utilizes the oxidation ditch type activated sludge treatment. So what does that look like?
All the water that goes down your drains makes a path to the WWTP through the 45.72 miles of sanitary sewer lines ranging from four to 36 inches in diameter serving 3,720 active customers. Once it arrives at the plant at 1800 N. Douglas Ave., the first step is to screen out large objects like rags, cans, sticks, and other things that can clog the works. City leaders emphasize not to flush disinfecting wipes, baby wipes, towelettes, paper towels, and facial tissues. These can get stuck on your side (your problem!) or further down the track. Courageous City workers had to fish many of these out of the intake during the height of Covid. So please do your part, put them in the trash!
The next step is to try to settle out the grit, dirt and any non-organic material by slowing down the flow in a sedimentation tank. The now-organic soup heads to the oxidation ditch to be handed off to the smallest sanitation workers employed by the City, aerobic bacteria and other microorganisms.
These one-celled wonders digest the organic materials in human waste when oxygen is present. So the brew is constantly aerated and agitated to make sure the little guys have the air they need to work. Every so often the wee buggies get worn out and a fresh crew is brought in to reactivate the culture. After working in the ditch, which is circular, the mostly digested liquid and biomass heads to the secondary clarifier to finish up. The residue of this feeding frenzy falls to the bottom as sludge and is removed, dried and currently is being hauled away to a site near Sutherlin for disposal. It is hoped that eventually the rich sludge will be able to be processed here and used as fertilizer and soil conditioner. To ensure there are no harmful viruses or bacteria the water is treated with chlorine, which later must be deactivated before being returned to nature.
Dried sludge, the residual from aerobic digestion plus clean water.
The WWTP never sleeps. It is in operation seven days a week, 24 hours a day. The plant can handle 13 million gallons/day (MGD) at a peak instantaneous flow. Typical WWTP flow is 1.0 MGD in dry weather and 3.5 MGD during wet weather. As a final step the water is tested for over 67 different contaminants, bacteria, and chlorine.
There is redundancy built into the system, which is good, as one of the old clarifiers, which was scheduled to be rebuilt, went on the fritz and jumped to the head of the “to do” list. To meet the requirements for a permit from the Oregon Department of Environmental Quality (DEQ), the old clarifier needs to be repaired and back on line by this Fall when water treatment volume again goes up.
Since the temperature of the water is critical, it usually cannot be returned directly into the river during the summer, hence the City ownership of the Middlefield Golf Course. Being able to irrigate with the now-safe effluent has allowed the city to honor its DEQ permit. In the face of increased water use the construction of the new effluent holding pond, capable of holding 10 million gallons, has been completed. This will give the City a chance to hold water for irrigation purposes. Pipes are being laid to carry the effluent to Bohemia Park and the Exit 174 interchange on I-5, where it will be used for keeping the grass green and happy without having to use our good drinking water. The treated water is cleaner than the river water it started out as, and with a filtration and disinfection treatment could be consumed. One day, mark my words, water will be so scarce that we will have to use it over and over again in a closed loop as the world’s population increases and our climate changes.
There is a perception among a segment of Grovers that the “water bill” – a misnomer right off – is too high. First, it is a utility bill that covers water use, wastewater treatment, and the stormwater system. In addition, there are three improvement charges, one for each of those areas. These improvement fees go to pay for debt associated with the past improvements as well as for future repairs and expansions. Sure, it would be nice to get your water for free, dump it straight into the river after dirtying it up and be done with it, just like the good old days, minus the typhoid.
However, that is thinking in a bubble. In the first part of this story, there was a brief history of some of the early attempts to clean up our Willamette River and the regulatory actions that have gone along with that effort.
In 1972 there were amendments to the Federal Water Pollution Control Act (Public Law 92-500), aka the Clean Water Act. This had big impacts on what water could be taken from rivers and the condition it needed to be in to go back into it.
The regulations have only grown from there, and the DEQ also has its requirements. In the past Cottage Grove has had to pay fines for violations but that has been drastically reduced as the WWTP has reached compliance. As the population grows so does the demand on the system and so costs increase. Having a small population means the costs are shared by fewer households and businesses than would be the case in a larger urban area. If you want a lower utility bill you could move to Eugene, but if you want the advantages of living in a small town, this is one of the costs of that choice.
The City’s water service, wastewater treatment, and storm drain system are operated as enterprise operations, kind of like businesses in that they try and pay for their services, as much as possible, by the rates paid by their customers. Like any business, the costs of running that operation have a nasty habit of going up.
If you have been following City Council meetings or social media, you have probably heard that the wastewater portion of the bill will be going up in July. At the April 12 City Council meeting John Ghilarducci of the FCS Group, which has been advising Cottage Grove on its utilities programs since 2008, presented a five-year Utility Plan for the council’s consideration. It had been presented at an earlier council meeting, but had to be updated in view of the failed clarifier.
First the good news: There were no proposed increases for either of the water charges or the storm drain charges for the next five years. New customers and existing money are seen as sufficient to keep the system at current levels as well as doing about $6.3 million in work while only borrowing $1.3 million. Stormwater improvement will be pegged at $1.7 million with no added debt.
There is major work to do with the wastewater side of things, however; $7.5 million will be needed for the WWTP improvements with the need to borrow $1.7 million.
After some lively discussion, acknowledging that utility bills are a touchy subject in the Grove, the debate was whether to go for a 12% increase for three years or to spread it out over a longer period. Concerns about putting hardships on local families were brought up. The distaste of kicking the can down the road was discussed and in the end, particularly in light of the increase to the wastewater portion of the bills would amount to about only $6.44 to an average customer’s bill, it was decided to grab the bull by the horns and get it done sooner rather than later. That would save the City, and ultimately the rate-payer, money in the long run. The vote was unanimous in favor.
Winners of the “If I Were Mayor” contest were announced during the April 26 City Council meeting. Co-first place high school winner MJ Raade, in her video presentation, expressed the idea of Citizens Advisory councils to help educate Grovers about the workings of the city government, and in particular the intricacies of the city utility programs and the costs involved.
Mayor Gowing was enthusiastic about the ideas. I am not sure if it is a direct outgrowth of Raade’s ideas but teaching tours are going to be offered at the City Water and Wastewater Plants.
They will be conducted by City Councilors so to schedule your tour, contact your ward’s councilor or one of the two at-large councilors, Mike Fleck and Ken Roberts, to get in on an interesting peek behind the scenes. I have gone through the works and it is fascinating!
Stormwater is its own system and hopefully it doesn’t get involved in the wastewater stream, but sometimes it does.
The City has contracted to have the old brick-lined manholes sealed, thus preventing stormwater from jumping ship and going down the wrong pipe. There are still a few other problem areas of cross connection that are being worked on.
The street sweeping is a way of ensuring that the stormwater that flows into the river through the storm drain system is cleaner, by sweeping up rubber, grit and other debris on the roads that would otherwise end up in the river. This is one way of reducing contamination, another is traps in some of the catch basins that collect sediment and oils, which are then sucked out using the City’s Vactor truck. The first bioswale is being tried out in the area behind Lincoln Middle School as a way to provide treatment of stormwater before it enters the river.
If you have made it this far in this discussion of cleaning up the water we use, thank you! And may you remember water is essential not only to us but to every living thing, let’s use it wisely and keep it clean so the fish you hope to catch one day are there for your grandkids and theirs as well.
Like those blue-and-white signs on the culverts say “No Dumping – Flows to the River!”
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