SAN FRANCISCO — The water of San Francisco Bay is getting clearer.
The San Jose Mercury News (http://tinyurl.com/qa6dm8v) reported Sunday that 150 years of tidal action has washed out to sea most of the sludge generated by Gold Rush miners using hydrologic mining technology upriver in the Sierra Nevada.
The good news comes with a downside, though. Scientists say the clearer water lets in more sunlight, which is causing more algae to grow in the bay.
Scientists monitoring the situation are concerned that new regulations may need to be imposed on the 42 sewage treatment plants around the bay if the algae growth isn't slowed significantly. The regulations would force the treatment plants to reduce the amount of nitrogen and phosphorous they pour into the bay. Nitrogen and phosphorous fertilize the algae.
The regulations could cost the sewage plants $10 billion, an expense that could lead to high sewage bills.