> But upgrading the urban wastewater-treatment facilities surrounding the bay would eliminate nutrient pollution, permitting more delta water to be directed to California’s farms and cities—a lot more water.
The main reason for "flushing" fresh water into the delta is to preserve the delta ecosystem. Without putting fresh water in the river, the salt water from the Bay works its way up the delta.
I tried a few searches to understand whether this wastewater issue is real or not, and the main "nutrient pollution" issue that comes up is not human waste, but instead fertilizer runoff from agriculture [1,2].
Upgrading wastewater treatment sounds great, but overall this author just doesn't seem to be honest.
[1] https://ucanr.edu/sites/DRAAWP/files/358402.pdf [2] https://www.mdpi.com/2071-1050/11/10/2845