The Santa Rita Water Reclamation Facility, the largest construction project in city history, is nearing completion and sending cleaner water into the Animas River.

But the smell of human waste persists in Santa Rita Park.

The $58.3 million project is expected to wrap up in October and should serve the city for the next 30 to 50 years, unless state standards for water quality change dramatically, said Assistant Utilities Director Jarrod Biggs.

The city spent $4.9 million of the construction project’s contingency fund and pushed back its completion date from May 21 to the end of October. Much of the additional spending was done at the city’s request to replace equipment that would otherwise have to be replaced later, Biggs said.

City Councilor Dean Brookie said he is pleased with the pace of construction and spending on the plant.

“It’s been a very seamless process,” he said.

Durango City Council raised utility rates steeply in recent years to pay for the new plant, which had to be built to meet state water-quality standards. The average city residential sewer bill is now $51.43 per month.

The plant has met the new water-quality standards and all the operational aspects of the plant are complete, said City Engineer Gregg Boysen. The new standards require wastewater treatment plants to remove more nitrogen and phosphorous from water before it is released into rivers. An overabundance of the nutrients can cause harmful algae blooms that can decrease oxygen in the water and kill fish.

A proactive approach to meeting the state standards was important because the state can levy fines on cities or prohibit cities from issuing building permits if standards are not met, Biggs said.

“We didn’t wait for the permit to come and then say: ‘We can’t meet it,’” he said.

Before construction of the facility, city officials also said the upgrades would eliminate the odor that wafts from the plant into Santa Rita Park.

“If this plant is built the way we suggest it be built, you won’t even know it’s here,” said former utilities director Steve Salka in 2014.

New carbon filters have been operating for about four months and will eliminate much of the plant’s “yuck factor,” Biggs said. They cannot eliminate the plant’s odor entirely, he said.

Brookie said the council will evaluate the smell once the plant is complete and make sure odor elimination has succeeded to the highest level of technical ability.

The millions invested in the plant have also created more redundancy and efficiency in the plant, Biggs said.

At the headworks building, where waste flows into the plant, double the amount of grit is removed from the water, ensuring less maintenance will be required at the plant over time, he said.

The primary clarifiers, huge tanks where solid waste settles out of the water, have been covered to collect the putrid gas they emit, he said. The gas is then sent to air filters, Biggs said.

The new aeration basins, where microbes process the waste, are four times larger than the basins they replaced and ensure more phosphorous and nitrogen can be removed from the water.

“All these pieces add up to a better product going into the river,” Biggs said.

The plant’s ability to produce electricity through methane has also been increased.

The plant’s final product, a dry solid, is trucked to the Bondad Landfill, which is expected to cost about $100,000 a year, Biggs said. The plant’s previous product, which was far more wet, required about $309,00 a year to truck to the landfill.

The city planned to create fertilizer with the waste, but the area did not have a large market for the material and it would have added $3 million to $4 million to the cost of the plant, Biggs said.

While the operational portions of the plant are largely complete, the city’s contractor, Archer Western, must finish the roads within the plant and lay sod in the field along Camino del Rio that was used as a staging area for the construction, Biggs said. Archer Western is expected to be finished by the end of October. Two additional buildings at the plant will be constructed separately from the $58.3 million contract.

Jaynes Corp., a local company, started three weeks ago on the new $8.3 million administration building. The building is expected to be finished in about a year.

It will have exhibits for the public about the wastewater treatment process and public restrooms. The building will be paid for out of wastewater treatment plant savings.

The utilities department also plans to ask the council to spend about $929,600 on a new building to store the city’s vactor trucks, which are used to clean septic lines. The building could be heated and plumbed to allow the staff to do maintenance on city trucks, he said. It will also be designed to match the other buildings, which will contribute to the cost, he said.

The city has no plans to replace the RV dump station it previously operated at the plant, because other dump stations exist in the city and the city has not heard demands for one, Biggs said.

“It’s not something that’s cropped up,” he said.

mshinn@durangoherald.com