Spokane Countys Utilities Division is studying options to meet the countys wastewater-treatment needs through the year 2020options that include building at least one major new treatment plant here, at a potential cost of as much as $110 million, or building up to three smaller treatment facilities in the Spokane Valley.
The division selected four wastewater-treatment alternatives and a sub-alternative last week, and gave those options to a private consulting firm hired by the county, says Bruce Rawls, the countys utilities director. That firm, the Seattle office of Omaha, Neb.-based HDR Engineers Inc., is expected to spend the next six months evaluating and comparing those alternatives, which will be incorporated into a wastewater facilities plan, Rawls says. A cost comparison of the various alternatives will be included.
The four alternatives being considered are:
To continue sending county-generated wastewater to the Spokane Regional Wastewater Treatment Plant, which is owned and operated by the city of Spokane, for the next 20 years.
To collaborate with the city of Spokane to build a joint wastewater-treatment plant within the city limits in an area generally located between Latah Creek and Spokane Community College. A site hasnt been selected for such a plant yet, and the size of a joint treatment plant hasnt been determined, Rawls says. He says treated effluent from such a plant could be dumped into the Spokane River, pumped into the Spokane-Rathdrum aquifer, reused for irrigation purposes, or a combination of those three.
To build a wastewater-treatment plant in the Spokane Valley in an area generally located several miles east of Spokane Community College and not far from the Spokane River. Again, Rawls says a site hasnt been selected, and the size of the plant hasnt been determined. Under this option, the treatment plant would be owned by the county, but could devote some capacity to treating city-generated wastewater. As part of this option, the county would look at a number of ways to reuse the plants treated wastewater.
To build at least three smaller treatment plants scattered around the Valley, all of which would be used solely by the county. Although sites havent been selected, Rawls says the plants, each of which might handle about 4 million gallons of effluent a day as opposed to 12 million gallons at a larger facility, would be located in areas where the treated effluent could be reused, such as near a golf course or a business that uses treated wastewater for its operations, Rawls says.
A sub-alternative, which could be added to any of the four alternatives already being considered, would include building a treatment plant in north Spokane near the Little Spokane River, in the vicinity of the community of Dartford. The consultants will study the benefits of recharging the Little Spokane River, which sometimes runs too low, with treated effluent from that plant. Rawls says the North Spokane plant option would have to be added to one of the other alternatives because it wouldnt handle all of the countys wastewater needs on its own.
The four alternatives are designed to help the county expand its wastewater-collection system to reduce the number of septic tanks located above the Spokane-Rathdrum aquifera goal the county began undertaking in the 1970s.
To reduce septic tanks, the county worked out an agreement with the city of Spokane in the early 1980s that allowed it to send county-generated wastewater to the city-owned Spokane Regional Wastewater Treatment Plant, Rawls says. Under that agreement, the county can send up to 10 million gallons of wastewater a day to the citys treatment plant, with the understanding that it can negotiate for more capacity in the future.
The county currently is sending about 6.5 million gallons of wastewater a day to the citys treatment plant, he says. Last year, the county realized that at its current rate of growth, which includes hooking up about 2,000 households a year in the unincorporated areas of Spokane, it would reach its 10 million gallon capacity limit by 2007, Rawls says.
Such a realization created concern because wastewater-treatment projects usually take between eight and 10 years to complete, Rawls says.
In the meantime, the city expressed concern to the county that there might not be additional capacity available for the county at its treatment plant, he says.
Those factors prompted the county to begin developing the wastewater facilities plan, which will evaluate ways the county could meet its wastewater-treatment needs for the next 20 years, while the county continues conversations with the city of Spokane to determine how much capacity is available at the citys treatment plant and how much of that might be available to the county.
Already, the county has predicted that by the year 2020, it will need to treat as much as 21 million gallons of wastewater a day, which creates a need for another 11 million gallons of capacity.
Rawls says that building a new wastewater-treatment plant likely would cost between $8 and $10 for every gallon of water the plant would treat in a day, meaning that an 11-million-gallon wastewater treatment plant would cost between $88 million and $110 million.
Drawing up a plan
In drawing up the wastewater facilities plan, the county simultaneously must complete an environmental impact statement (EIS) that would address various environmental issues, such as water-quality concerns, visual impacts, and potential impacts to fish and fish habitat. The EIS wont focus on the environmental impacts at a particular site for a new plant, but instead will consider general impacts on the environment, Rawls says.
A public meeting was held last month to determine what issues the public would like to see covered in the countys EIS. Rawls says at least two more public meetings will be held, likely in January and in mid-2001, to discuss the pros and cons of the four alternatives.
By the end of next year, the county expects to have completed its wastewater facilities plan, which will include the EIS. The plan will include the utilities divisions preferred alternative, and will be forwarded to the county commissioners for a final decision on which alternative the county should pursue, Rawls says. At that point, the county will start trying to budget for the selected alternative.
Ideally, it should take another five to six years to build a new wastewater-treatment plant, if thats the option selected.
My preference is for the city and the county to keep working together toward a new regional wastewater-treatment plant, while we utilize the citys plant for as long as possible, Rawls says. I see that as the least costly alternative.
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