By Deb Murphy
With dust storms under control on Owens Lake, Mono Lake has made it to the top spot for PM-10 pollution.
The solution is simple: just raise the lake level to 6,392 feet above sea level and the northeast shore, the source of the fine particulate matter with the potential to cause health issues, will be underwater. Operating under a State Water Resources Control Board decision for the past 23 years, Los Angeles Department of Water has been following all the rules but is still 10-feet short of goal and the lake basin exceeded federal standards 33 times in 2016.
Phill Kiddoo, air pollution control officer for Great Basin Unified Air Pollution Control District, is encouraging all the stakeholders to update hydrological models to see if that 6,392-foot goal is reachable under the Control Board’s guidelines. And, that study needs to be done soon.
Like everything involving water and LADWP, it’s complicated. Here’s the simplified thread:
- In 1940, LADWP was permitted to divert water from four creeks that ended in Mono Lake.
- The lake level dropped like a rock, at the lowest level since an epic drought prior to recorded history, according to Mono Lake Committee Executive Director Geoff McQuilken. Law suits ensued.
- The result of those suits was the Control Board’s decision requiring 60,000 acre-feet back in the diverted creeks and limiting LADWP’s diversions. Between lake levels of 6,377 and 6,380, the department can take 4,500 a-f; over 6,380, the diversion goes to 16,000 a-f.
- The decision was to remedy a number of environmental issues, including air quality. According to Kiddoo’s progress report presented at Great Basin’s May board meeting, raising the lake level “was determined the only feasible method to sufficiently reduce emissions to comply with the federal PM-10 standard.”
Original predictions indicated it could take from nine to 38 years for Mono Lake to reach that 6392-foot level. But, LADWP’s water license is up for re-evaluation by the Control Board if the lake is still short of the target in 2020. According to Great Basin’s analysis, it’s not going to hit the target. “The lake level projections are based on data and a model from over a quarter century ago, based on data which appears to be inadequate for current and future conditions,” Kiddoo said.
What about California’s epic drought and climate change? That’s not really relevant, said Kiddoo. The mean flows from the creeks between 1941 and 1990 are just 100 a-f more than mean flows from 1995 to 2017. Mono Lake levels have bounced up and down, reflective of run-off, but that 6392 goal is not close to being reached.
Methods used on Owens Lake to reduce or eliminate dust storms won’t work on Mono. “This is a different lake,” said McQuilken. As a National Forest Scenic Area, Mono carries additional protections and requirements. LADWP has pointed to concern for rate-payers to justify eliminating irrigation water to Mono Lake grazing leases. But, the Mono Lake Committee talked to DWP rate-payers back in the 80s and 90s. “They didn’t mind paying a little extra to restore Mono Lake,” he said.