Lind’s new treatment facility comes online

Almost exactly a year after breaking ground at the Wastewater Treatment Plant in Lind, the project is reaching completion and is fully operational.

Minus a few minor installations, making some aesthetic improvements and working out any final glitches in the system, the Town of Lind intends to sign the final paperwork with Kearsley Construction, Inc., at the end of April, designating the project as complete.

The town began drafting plans for the construction of a new treatment plant over 15 years ago, and the plan finally was put in motion following funding from the Department of Ecology.

The total development cost, set at $3.2 million, has been 90 percent funded by the Centennial Grant Program through the Department of Ecology. The Centennial Grant Program is funded through state dollars and is dedicated to improving water quality infrastructure in financially troubled communities.

Kearsley Construction received the bid for the project, after coming in as the low bidder with a base bid of $2,553,567. The town hired the construction company for the project in October 2012, before breaking ground at the site on April 22, 2013. The Town of Lind retained USKH, Inc., civil engineer Alan Gay as the primary engineer on the project.

While the treatment plant has been constructed on the same site as the previous plant, the existing 1953 plant has been demolished. The repairs and constant maintenance costs of the previous plant had become a financial burden to the town, which prompted the decision to move forward with construction of a new facility.

With improved technology and more efficient equipment at the plant, Gay estimates the new treatment plant is going to be a huge benefit for the town.

The town currently employs Franklin Ridgeway to maintain and monitor the plant, and Ridgeway is at the plant two days a week. Town employees do minor maintenance and monitoring of the plant during the weekdays.

The treatment process as a whole is complex, as the flow amounts, bacteria, nitrate and ammonia levels have to be monitored on a fairly regular basis to ensure the waste is being handled and disposed of properly.

The facility is designed with technology built in to assist employees of any potential risks or glitches in the system. The improved monitors inside of the office and shop area, allow Ridgeway to take samples from the plant and run tests, while still being able to monitor the tanks on screens set up throughout the office.

Gay explained the entire system has been designed with bypass systems and backups, in the case any portion of the facility should fail. Each portion of the plant has a separate bypass, allowing the facility to remain operating if only one portion of the plant breaks down.

The basic operation of the plant consists of wastewater flowing from town to the plant, and passing through an initial screen, which collects solids such as rags or foliage.

Before the water reaches the physical plant, it runs through a box that monitors the water levels and also allows Ridgeway to collect samples for fecal coliform levels, tested on a weekly basis, and the biochemical oxygen demand, tested less regularly, both tests which measure the amount of bacteria coming into the plant.

When the solids come into the rotating fine screen, the screen slowly lifts the solids to the surface and they are compacted slowly in an auger. These solids are disposed of in a bin located beside the treatment plant.

The water rate is monitored by a variable frequency drive, which keeps the flow going into the plant even and consistent.

The water passes through the valve vault into a channel before beginning the fermentation process. It goes through a clarification process, in which after completed, all of the activated sludge is moved back into the channel.

It is during this process the bacteria starts undergoing treatment, and in turn, the monitoring of the nitrogen levels begins. Gay explained this is the main portion of the bacteria treatment portion, as bacteria does not like air.

Beside the channel are two aerated basins where air is used for the “bugs,” or good bacteria, in the water system to help balance the nitrate levels. The air helps activate the bugs and converts ammonia into nitrates. The water continues through multiple cycles to ensure the nitrogen is at a balanced level, and Gay explained lowering the nitrogen is the hardest step.

Air lift pumps within the basins return the sludge to the channel before eventually into digesters. A probe at one end of the facility helps monitor the oxygen levels and ensures the air does not poison the bugs during the denitrification process.

Gay said a portion of the treated water at the plant is used to continue running the pumps, washing the screens and cleaning the belt filter press, located in the interior of the shop.

As all of the waste has to be monitored, the solids are moved through the system into the belt filter press. After going through the press, they are discharged onto a manure spreader, which spreads the waste on the 22 acres of land, and three beds, next to the plant.

Gay said the solids are taken out once or twice a year and the application is rotated between the beds, where they are also monitored. The waste can be tilled into crusted wheat grass, after the town obtains a permit to do so.

Within the lab, Ridgeway collects samples and tests them for oxygen, ammonium and nitrates. He collects two samples, one that he conducts his tests with, and another set of samples that is sent to an accredited lab.

“The biggest benefit of this facility is, one: it requires less operational attention,” Gay said.

“Two, it complies with all of the new permits, and three, it is something that will allow the town to grow.”

The plant has the capacity to serve an estimated 660, and currently is being used by just over 500 Lind residents.