The Iowa Nutrient Reduction Strategy (INRS) includes very little regulation. In fact, one of its selling points is that, for non-point sources such as farms, its recommendations for reducing nutrient loads in Iowa’s surface waters are completely voluntary.
But for point sources, such as wastewater treatment plants and certain industries, the strategy does include some regulation. This disparate approach has been the subject of criticism, notably from the Des Moines Water Works, but the Iowa Department of Natural Resources maintains that the INRS creates a better regulatory environment than sweeping federal standards would.
Adam Schneiders with Iowa DNR’s Water Quality Bureau says it works like this: some municipal wasterwater treatment facilities and industries are mentioned by name in the Iowa Nutrient Reduction Strategy. Those will be required to perform a feasibility study examining lower nutrient discharge when they renew their wastewater discharge permit through the Iowa DNR, a process that usually occurs one every five years. The facilities that appear by name in the strategy were selected by the DNR because they discharge over one million gallons of water per day. Conceivably, a facility operating on such a scale could handle the financial side of reducing nutrient loads.
But what if it can’t? Schneiders says that, after the feasibility study, the facilities will implement their own recommendations for a year, at the end of which time Iowa DNR will set reachable discharge limits. This turns the normal limits-first permitting process on its head, and, Schneiders says, takes advantage of the average lifespan of a wastewater treatment facility – 20 years.
Some of these plants lend themselves to be retrofitted very easily, and in some cases, they may actually be able to save money by changing some of those operations, they may be able to get some of these, the nitrogen removal and the phosphorus removal just by tweaking things, because their plants are designed in a flexible way, and they can save money because they’re not using blowers or certain electricity costs.
So, who knows what may come out of it? It’s an exciting time to see what’s possible.
Ideally for Iowa DNR, limits set by the facilities themselves on a case-by-case basis and the opportunity to save money will make nutrient reduction on the part of point sources more attractive than a mandate from EPA.