Phosphorus cleanup could get expensive for PRWID customers
A report about phosphorus and nitrogen in sewer water is not exactly earth-shaking. On the other hand, it is an issue that could cost you as much as $16 extra every month on your sewer bill.
That $16 is what engineers estimate it would cost to remove all but the barest traces of phosphorus and nitrogen compounds from the Price River Water Improvement District's effluent at the Wellington Wastewater Treatment Plant.
According to John Mackey of the state's Division of Water Quality, standards are not that strict yet. But if the Environmental Protection Agency or the state ever decide that all systems should install the best available technology in their treatment plants, that would be the impact on PRWID and its customers.
Less stringent requirements on phosphorus only would cost an extra $1.50 per customer per month.
Mackey was briefing the PRWID board last week on a whole range of possible options that the environmental regulators may take. The DWQ has prepared a statewide analysis of treatment plants to calculate the various impacts of those options. The added costs would come from construction of facilities and ongoing maintenance and supplies.
So what's the big deal? All life on earth depends on phosphorus and nitrogen, which, like carbon, hydrogen and oxygen, are found in every cell. These elements are not evil in themselves.
However, there is no question now that excessive levels phosphorus and nitrogen can ruin water quality and habitat in lakes and streams. Ponds and lakes can become completely covered with green scum from algae that reproduce like mad when chemical nutrients support their lifestyle.
Algae, being plants, are good because for at least 3 billion years they have been pumping out lots of oxygen through photosynthesis while they are alive. When they die, though, they sink to the bottom and rot. If they are overabundant, the rotting depletes oxygen and can suffocate fish in extreme cases.
Utah has its own regulations to control sewage emissions, Mackey said, but these are applied on a site-specific basis. A treatment plant near Jeremy Ranch, for example, feeds into a stream that is considered prime fishing. It must apply the strictest rules.
During a discussion among PRWID board members, it was apparent that stringent state- or nation-wide standards would not be welcome or even effective in the district.
PRWID manager Jeff Richens explained to the board that any one-size-fits-all regulation on levels of phosphorus could be unfair to some sewer districts. For instance, the toughest standards could force PRWID to adopt sewage treatment strategies that would make the treated wastewater lower in phosphorus than the river water coming into its culinary water plant at Castle Gate.
That algae bloom that caused so many problems recently took place upstream from the Price City and PRWID water plants, which indicates that the phosphate and nitrogen levels in the incoming water are high enough to sustain that kind of growth even before entering the wastewater system.
Second, phosphorus and nitrogen compounds enter rivers and lakes from other sources than sewage treatment plants. Runoff from lawns and farm fields, for instance, carry fertilizer into streams.
Now for a money-making from chemistry hint. Phosphorus, while a problem in some cases, is a crucially important element in limited supply, with relatively few sources in the world. There is a market for the stuff. Phosphate rock was going for about $50 per ton last year. Anyone who patents a cheap process for extracting usable phosphate compounds for fertilizer from waste water or polluted ponds stands to make some money.