The Washington State Department of Ecology has recently submitted a final version of a dissolved oxygen total maximum daily load for the Spokane River and Long Lake. The purpose of this TMDL is to help restore necessary dissolved oxygen to aquatic life.
This TMDL greatly restricts the amount of oxygen-demanding substances that are discharged by wastewater treatment plants into the Spokane River. These include ammonia and phosphorus. Phosphorus causes algae blooms, which consume dissolved oxygen.
Such a TMDL is a requirement of the federal Clean Water Act of 1972. The Idaho wastewater dischargers support the concepts of this document.
Recently, the Idaho dischargers have been criticized for filing petitions for a “dispute resolution” with the Department of Ecology, along with delaying the efforts to help “clean up” the Spokane River. Nothing could be further from the truth.
Over the years, the Idaho dischargers have spent hundreds of millions of dollars on expanding and improving their treatment plants. These improvements were necessary to provide better wastewater treatment as well as to expand capacity and remove septic tanks over the precious aquifer.
Coeur d’Alene was one of the nation’s first treatment facilities to provide secondary treatment in 1939 (some 33 years before it was mandated by the Clean Water Act). Since its original construction, some $60 million has been spent on expansion and improvements, including phosphorus removal. About $4 million has been spent for three advanced filtration (tertiary) pilot units to gather data to make an informed choice for a full-scale tertiary treatment process in the near future. A $13 million improvement project is under construction.
To the west, Post Falls operates an advanced secondary treatment plant that utilizes biological nutrient removal processes and even advanced ultraviolet disinfection. Currently the plant is undergoing $11 million in improvements consisting of upgrades and expansion to the facility.
The Hayden Area Regional Sewer Board was founded to remove septic tanks near Hayden Lake and over the Rathdrum Prairie Aquifer. HARSB’s secondary treatment plant reuse farm irrigates livestock crops and poplar trees with all the plant’s effluent during the growing season. The HARSB facility also has a private/University of Idaho research facility that is testing an advanced tertiary treatment process.
So why did we file for dispute resolution? Two reasons: equity and fairness.
Washington’s DOE has erred substantially in calculating phosphorus loadings for the Idaho dischargers. Two quantities are needed to calculate the allocation for each discharger in pounds per day. Future expected flows from the plants must be forecast and the allowable concentration of phosphorus must be determined.
First, we take exception with the flows forecast in the TMDL. Idaho dischargers were not granted adequate flow allocations for the next 20 years, much less than will be ultimately needed. Both the city of Spokane and Spokane County were granted much higher flows per person than were Idaho cities. Flows were nearly three times the allowance for Post Falls and 60 percent higher than Coeur d’Alene. No justification for this difference is offered in the document.
Next is the assumed concentration of phosphorus. Why were the Idaho dischargers given an allocation of 36 parts per billion while both the city of Spokane and Spokane County given a concentration of 42 ppb – nearly 17 percent higher? We know of no licensed professional engineer who will certify that any known technology can achieve this nearly impossible level of 36 ppb. This places the Idaho dischargers in great jeopardy of being subjected to enforcement actions that could include large fines.
When the TMDL flows and concentrations are added up, Washington receives about 85 percent and Idaho receives only about 15 percent of the allowable pounds per day.
The allowable pounds per day will eventually limit the amount of discharge, and therefore the amount of growth. Post Falls sponsored an economic study that reveals serious economic impacts over the next 20 years. Once the dischargers reach their maximum allowable pounds per day, one of two scenarios will occur: Either new technology will have to be at hand to achieve even lower concentrations of less than 36 ppb, or a moratorium on all growth will have to be enacted.
In summary, the Idaho dischargers are moving forward with implementing highly advanced tertiary wastewater treatment. We are asking for equity, fairness and limits that are achievable and sustainable. We have been, and continue to be, responsible stewards of our environment as well as fair to our ratepayers.
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