Research from scientists say that the regional sewage treatment plant discharges wastewater into the delta and this is a large source of ammonia.
According to reports on SacBee the scientists are reviewing two recent San Francisco State University studies that report the effect of high ammonia levels in the delta.
While ammonia does not make fish unsafe to eat, the studies indicate it interrupts the natural food production of the tiny aquatic animals that salmon, smelt and bass feed on, the AP report on SacBee says. Populations of all three species are in decline.
If the findings hold up under peer review, the costs of cleaning ammonia from the water could be as high as $1 billion, which could triple the region's monthly sewage bills, says the Sacramento Regional County Sanitation District.
Ammonia Threat to Fish
US - Ammonia from sewage farms could be killing fish in the Sacramento-San Joaquin Delta.