I'm no fan of Seattle's government, but FWIW, I have lived in one of those Desert cities (San Diego). They have a sewage pipe that goes about 2.5 miles into the ocean [1] and spews out "lightly" treated sewage water. There is no secondary treatment, they even have a waiver to do this (I believe from the federal government or possibly state government) [2].
In Seattle, on the other hand, we are not allowed to dump water at that level of contamination into lake Washington or the Sound. It costs a LOT of money to do secondary treatment, and we are taking it even further by building a massive underground holding tank to make sure that we don't dump any overflow in the event of heavy rain.
This is more than what is federally required, but in this instance I actually think the extra cost is worth it.
In Seattle, on the other hand, we are not allowed to dump water at that level of contamination into lake Washington or the Sound. It costs a LOT of money to do secondary treatment, and we are taking it even further by building a massive underground holding tank to make sure that we don't dump any overflow in the event of heavy rain.
This is more than what is federally required, but in this instance I actually think the extra cost is worth it.
[1] https://www.sandiegoreader.com/news/1989/sep/21/end-pipe/ [2] https://en.wikipedia.org/wiki/Point_Loma_Wastewater_Treatmen... [3] https://www.surfrider.org/campaigns/san-diego-secondary-trea...