Submitted by Don Russell, Lakewood.
With the approval of the Washington State Department of Ecology, the City of Lakewood’s contractor HAB Aquatic Solutions on March 24-25, 2020 discharged 238,400 pounds of a saturated solution of the acid salt aluminum sulfate and 135,180 pounds of a saturated solution of the alkaline salt sodium aluminate into 33-acre Waughop Lake.
This operation involved the tank truck delivery and on shore tank storage of these two liquids and its transfer to a distribution barge, whereupon it was discharged into Waughop Lake.
The aluminum that was discharged into the lake through trailing hoses mounted on the barge’s booms was in a soluble toxic form that required its transformation by reaction with a buffer or antacid (sodium alumninate) being discharged through paired adjacent trailing hoses into relatively insoluble nontoxic aluminum hydroxide. Aluminum hydroxide is a flocculent material that as it settles through the water clarifies the water and inactivates the phosphorus that fuels the harmful cyanobacteria blooms in lakes that have an excess of this phosphorus nutrient.
The initial notable effect on the lake of this operation is a turquoise coloration that is quite striking.
This effect is caused by light reflecting off of small particles of the aluminum hydroxide during the initial phase of transformation of the toxic form of dissolved aluminum to the nontoxic form of insoluble aluminum hydroxide. It is during this initial phase of the discharge of these two chemicals that the applicator controls the acidity (pH 6-8) of the lake’s water to assure that the toxic form of aluminum is mostly converted to nontoxic aluminum hydroxide.
After several days, this coloration disappears as the aluminum hydroxide particles all settle to the bottom of the lake to blanket its sediment. When this happens the lake’s water becomes very clear. The aluminum hydroxide blanket that forms on the surface of the lake’s sediment is intended to prevent the release of phosphorus from the sediment back into the lake’s water column thus denying harmful cyanobacteria the nutrient that fuels their explosive population growth (blooms) during the summer.
Such aluminum (alum) treatments are predicated on the assumption that it is phosphorus release from sediment that is the proximate cause of a lake’s recurring harmful cyanobacteria blooms.
Unfortunately, this assumption does not apply to Waughop Lake. The cause of its recurring harmful cyanobacteria blooms was the inadvertent discharge by Pierce College of phosphorus rich human sewage into Waughop Lake. This condition was first noted and reported to the City of Lakewood in 2007 by Don Russell.
It wasn’t until 2017 that it was finally discovered that Pierce College’s intermittent 40 year discharge of human sewage into Waughop Lake was due to an unknown (at the time of Brown & Caldwell’s 2014-2015 study of Waughop Lake) sewer line connection to Pierce College’s stormwater drainage system. Nor was it considered during the development of the 2017 Waughop Lake Management Plan that recommended an alum treatment of Waughop Lake as a lower cost temporary relief from harmful cyanobacteria blooms to a more costly but preferred removal of the layer of nutrient rich sediment laid down by 65 years of Western State Hospital’s discharge of slaughtered animal waste, manure and human sewage followed by 40 years of Pierce College’s discharge of human sewage into Waughop Lake.
Waughop Lake’s response to the 2017 discontinuance of the discharge of Pierce College’s phosphorus rich human sewage into Waughop Lake was the beginning of its transformation from years of being a turbid water harmful cyanobacteria infested lake to a clear water excessive aquatic plant growth dominated lake, no longer in need of an alum treatment. Although this fact was pointed out in 2019 to Ecology and the City of Lakewood, nevertheless Ecology approved and the City of Lakewood proceeded to hire a consultant to formulate a Waughop Lake Alum Treatment Plan and hire a contractor for a total of $420,000 to apply an unprecedented in quantity (dosage) of chemical (aluminum sulfate and sodium aluminate) discharge into Waughop Lake.
The environmental consequence of the March 24-25 discharge of 238,400 pounds of aluminum sulfate and 135,180 pounds of sodium aluminate into Waughop Lake remains to be seen. The likely result will be a significant change in the species and quantity of algae and aquatic vegetation that grow in the lake, a decline in the waterfowl and eagle population, and a demise of the lake’s carp and largemouth bass fishery. Whereas these post alum treatment ecological effects are likely to occur Ecology, WDFW and the City of Lakewood appear to be disinclined to monitor and advise citizens of these post alum treatment adverse environmental effects.