Politics Blog

Lake Whatcom cleanup a long and complex task

A foggy morning on Lake Whatcom, Jan. 2, 2013.
A foggy morning on Lake Whatcom, Jan. 2, 2013. THE BELLINGHAM HERALD

The latest annual report on Lake Whatcom water quality seems to be frustrating people who want to see dramatic improvement and drastic measures to get there.

In a recent news report, lead Lake Whatcom researcher Robin Matthews said there are no quick fixes for lake water quality issues that affect the drinking water supply for Bellingham and nearby areas. Matthews is director of the Institute for Watershed Studies at Huxley College of the Environment, Western Washington University.

Bill Reilly, Bellingham's stormwater utility manager, agrees. Like Matthews, Reilly notes that it took decades for the lake to get to its present condition. The gradual growth of residential development in the watershed has increased runoff into the lake, and that runoff carries the phosphorus that triggers algae growth. The algae can clog the city's water treatment system and provide food for bacteria that deplete the dissolved oxygen in the water.

Reilly is on the front line in the effort to make drastic reductions in the amount of phosphorus now getting into the lake.

I wasn't able to make connections with Reilly in time for my earlier report on Matthews' research, but I wanted to share his explanation of what the city, Whatcom County and Lake Whatcom Water and Sewer District have been doing to get the lake's water quality headed in the right direction. Matthews' most recent reports indicate that the deterioration of the lake may have been halted, but past efforts have yet to show any improvement.

Reilly said the best way to keep phosphorus out of the lake is to prevent runoff from occurring. That means setting up infiltration systems that allow rainwater to soak into the ground instead of flowing into the lake.

But doing that on a large scale is challenging, since rainwater infiltrates poorly into the kinds of soils that surround the lake, and no large swaths of empty real estate are available in the lakeside areas where infiltration systems might have the most impact.

That means that in the near-term, the city has been installing some systems that remove phosphorus from runoff before it hits the lake. Those systems can now remove 50 to 60 percent of the phosphorus.

But that's not good enough, Reilly said. The Washington Department of Ecology has identified Lake Whatcom as impaired since 1998, and the state agency has been pushing local governments to make deep and dramatic cuts in pollution from runoff. That means returning the lake to something a lot closer to its natural level of quality even though much of the lake watershed is now a human-built environment.

"The lake would have healthy levels of algae and oxygen if 87 percent of the developed area around the lake stored water during rainstorms, filtered water through the soil, and evaporated water as if it was covered by forest, " an Ecology press release said in 2013.

That means that runoff treatment systems are not the answer, Reilly said. 

"If you're trying to reach the goal of 87 percent, you know that you have to do more things," Reilly said.

If you live in the lake watershed, the "you" Reilly is talking about could really mean YOU.

The city and county have been reaching out to watershed homeowners with a Homeowner Incentive Plan that uses state grant money to help pay for home-based infiltration systems to reduce the volume of rainwater flowing into the lake, house by house. Up to $6,000 in financial assistance is available for those whose projects are accepted, thanks to a state grant.

There are now about 7,000 homes in the watershed, and the number is still rising a bit each year.

"To really get to where our goal is, we need to visit every one of those properties and have them do something on their properties," Reilly said. "That's a huge undertaking."

For now, city and county officials are relying on incentives, rather than mandates, Reilly said.

This city report is chock full of information about the level of development that already exists around the lake.

 In a related matter, the city of Bellingham is now in the early stages of planning eventual construction of a multi-million-dollar prefiltration system that will remove most of the algae from water pumped from the lake into the city's existing water treatment plant. Prefiltration is meant to eliminate the risk that a big algae bloom could clog the treatment plant enough to reduce the city's water supply. That actually happened in 2009, when warm and sunny weather helped lake algae thrive.

One reader called to ask me why the city would need such a pre-filter. Why not just move the city water system intake to a different part of the lake, where there is less algae?

Assistant Public Works Director Eric Johnston said that idea was evaluated and rejected. Moving the city water intake is more expensive than it sounds, and there are few areas of the lake without some level of algae and other microorganisms, Johnston said.

The clogging of the existing water treatment system is only one algae-related problem. The other is the fact that treating city water to remove algae and other microorganisms involves the use of disinfectants that leave small traces of carcinogenic byproducts in the water that comes out your tap. Prefiltration would mean less disinfecting and fewer worrisome byproducts in drinking water.

Johnston said many cities relying on surface water for drinking supplies are already using prefiltration systems for that reason.

It's worth noting that Matthews, the Huxley lake scientist, agrees that a prefiltration system is a good idea.

  Comments