Lake Whatcom Water Quality Continues to Decline

April Markiewicz is an environmental toxicologist and the associate director of the Institute of Environmental Toxicology in Huxley College of the Environment at Western Washington University. She is also an advocate for the protection of Lake Whatcom and is the president of the People for Lake Whatcom Coalition.

Well, another year has passed and the latest Lake Whatcom Monitoring Report by Matthews et al. (2008) has just come out. The data once again show that our community’s primary drinking water source for the 96,000-plus Bellingham and county residents is continuing to decline in water quality. This is not too surprising since we continue to treat the lake and its surrounding watershed as our personal scenic haven for living, recreating and in some cases making a profit.

On the other hand, even if we stopped all further residential development, recreational activities on and around the lake and logging in the watershed tomorrow, the degradation in water quality would continue. The reason is that the natural ability of the lake to cope with inputs of nutrients and other pollutants has been overwhelmed. Huge volumes of stormwater runoff are entering it from existing houses, lawns, driveways and roads, as well as from deforested lands in the watershed.

The culprit causing most of the water quality degradation in the lake is excessive phosphorus (Matthews et al. 2007; Pickett and Hood, 2008). Phosphorus is most commonly found attached to soil particles, so it is not surprising that the primary sources of it are from construction sites, existing residential development and logging/road-building practices that expose nutrient-rich soils to erosional processes.

Since the primary land uses in the Lake Whatcom watershed are urban (31 percent) and forestry (79 percent), that equates to potentially significant sources of phosphorus going into the lake (Whatcom County, 2008; Pickett and Hood, 2008). Once in the lake, phosphorus acts directly as a fertilizer for microscopic algae and larger aquatic plants, and indirectly by providing a larger food source for bacteria that feed on the dead and decaying plant life.

The direct effects result in algae ”blooms” that can turn the water green, cause unpleasant odors, clog water treatment filtration systems, increase health risks associated with disinfection by-products created during the treatment process and cause taste problems in the finished drinking water.

The indirect effects result in severe oxygen depletions in the deeper sections of the lake as bacteria feed on all the decaying organic matter and use up the oxygen. Low oxygen levels (<4 mg/L) not only harm aquatic organisms and cause fish kills, but also cause the water to become acidic (USEPA, 1986).

The acidic water acts to dissolve the phosphorus, metals (including lead and mercury) and other pollutants in the sediment into the surrounding waters where they can become distributed throughout the lake when it mixes during late fall. These compounds are then available for uptake by aquatic organisms and fish in the lake that are in turn eaten by us.

Oxygen depletions became so severe in Basins 1 and 2 (map on page 4) over the years that in 1998 the Washington State Department of Ecology (Ecology) listed Lake Whatcom as an impaired waterbody as defined in Section 303(d) of the Clean Water Act. Three years later the Whatcom County Health Department and the Washington State Department of Health issued a health advisory for smallmouth bass and yellow perch in the lake due to mercury contamination (WDOH, 2001).

The source of the mercury coming into the lake was primarily from the atmosphere (Paulson, 2004), but rather than sinking to the bottom and staying there it was being recycled back into the water during low oxygen conditions in the summer. The health advisory is still in effect.

Ten years have passed since Ecology listed Lake Whatcom as impaired and since then water quality has not only continued to decline, but has accelerated in its rate of degradation over the last six years (Matthews et al. 2007). Ongoing water quality monitoring by Matthews et al. has documented those changes in all three basins of the lake during that time.

In 1998 the water quality data showed Basin 1 as the most impacted, Basin 2 to a lesser extent and Basin 3 as being relatively unaffected. By 2002 water quality had degraded further to the point that Basin 2 had nutrient levels similar to those in Basin 1 and in Basin 3 elevated phosphorus levels were being detected for the first time. As of last year Basin 3 was showing the same increases in phosphorus, chlorophyll and blue-green algae coupled with dissolved oxygen depletions in the summer as the other two basins (Matthews et al. 2007).

The latest data show that the biological activity in the lake is continuing to increase and that water quality is continuing to be degraded throughout the entire lake, though not as rapidly as it did in the last few years (Matthews et al. 2008). This is probably due to the usually cold weather we had in May and October last year.

The cooler spring and fall prevented the deeper sections of Basins 1 and 2 from stratifying for as long a time, which meant that the deeper waters were without oxygen for shorter time (~ 2 months) as well (Matthews et al. 2008). This resulted in less phosphorus and other pollutants in the sediments being dissolved and released back into the water during the summer. Consequently, the 2007 water quality and biological data were not consistent with historical patterns. In summary:

• Ammonia, hydrogen sulfide, total phosphorus (Figure 1), zinc, and mercury, i.e., chemicals associated with the sediments, as well as diatoms (Chrysophyta) and blue-green algae (Cyanobacteria) numbers were lower than last year’s levels in all three basins.

• The downward trend for dissolved oxygen in the deeper sections of Basins 1 and 2 seems to have flattened out at least temporarily (Figure 2); however, the levels are still well below the concentrations necessary to support aquatic life.

• Basins 1 and 2 were without oxygen below the depth of 15 meters by August. The implications are that bacterial productivity in the deeper water and sediments is still increasing despite the cold spring weather that slowed down lake stratification.

• Dissolved inorganic nitrogen (nitrate/nitrite), iron, chromium, numbers of green algae (Chorophyta) (Figure 3) and chlorophyll (an indicator of algal growth) (Figure 4) were higher than 2006 levels.

• Trihalomethanes (THMs), created during the disinfection process and known to be cancer-causing were much higher than last year’s levels (Figure 5). This was unexpected since the city had changed the chemicals it had been using in the treatment process, which resulted in a substantial decrease in THMs in 2006. The sharp increase in 2007 indicates that whatever benefits the new chemicals were providing have been counterbalanced by continued increases in particles making it through the treatment process.

The short answer is that the lake is still continuing to decline in water quality throughout all three basins. The longer answer is that we need to consider the effects weather conditions have on the lake in addition to and coupled with the ongoing impacts to the lake from construction, existing development, recreational activities and forestry practices. The data from 2003-07 are showing how important climate and temperature conditions can be in affecting the chemical and biological processes in Lake Whatcom.

Warmer temperatures during 2003-05 served to increase biological productivity in the lake, speed up thermal stratification in Basins 1 and 2, lengthen the time that the deeper sections of the lake were without oxygen, prolong the time that sediment-bound phosphorus and other pollutants could be dissolved and released back into the water and accelerate nutrient cycling throughout the lake. The implications of the potential effects that global warming may have on the future water quality and quantity in Lake Whatcom are disheartening even to consider.

The colder weather we had last year slowed down some of those processes and changed how they interacted together. Yet the end result was still increased biological productivity that, in turn, adversely affected water quality in the lake, as well as increased the amount of cancer-causing THMs in our tap water.

The key to stopping the degradation in Lake Whatcom is to remove phosphorus inputs into it. That message is being strongly reinforced by the draft Lake Whatcom TMDL (Total Maximum Daily Load) study recently completed by Ecology (Pickett and Hood, 2008).

The TMDL report identifies existing residential development as the primary source of phosphorus entering the lake and recommends 74 percent fewer acres of development, based on 2002-03 land uses to attain phosphorus limits needed to bring the lake back to natural loading conditions. If those land uses had allowed maximum build-out, then an 89 percent reduction of developed acres would be required.

Additional efforts will be needed by the city of Bellingham and Whatcom County, as well as by every resident living in the watershed, to stop phosphorus loadings to the lake. The city and county can no longer rely on stormwater treatment vaults to control phosphorus inputs since subsequent studies have shown they are not very effective (Matthews et al. 2007; 2008).

Each homeowner in the watershed will also need to start taking responsibility for retaining stormwater runoff on her/his property by infiltrating it into the soil or using it for watering purposes. Strategies to accomplish this may include installing rain barrels, replacing lawns with native vegetation and replacing impervious driveways, patios and other “hard” surfaces with pervious materials.

Less draconian measures will involve continuing to purchase developable land in the watershed as part of the Lake Whatcom Land Acquisition Program to keep those lands from being developed and contributing even more to the current phosphorus loadings.

Another strategy that was not considered in the TMDL study is to reduce logging operations in the watershed. The Lake Whatcom Landscape Plan currently allows logging operations, though under very tightly controlled conditions. The proposed reconveyance of 8,400 acres of Forest Board Lands in the watershed back to the county by the Washington State Department of Natural Resources (WDNR) will help in reducing phosphorus loadings to the lake over the long term.

According to the Draft Memorandum of Agreement, the county will manage the reconveyed lands “primarily for passive park and recreational experiences” much like they do the Stimson Reserve (Whatcom County, 2008). Under this management plan the potential for phosphorus loadings will be much less than if retained under current WDNR forestry management practices. County Executive Pete Kremen and WDNR Commissioner Doug Sutherland are to be commended for their efforts.

The alternative of leaving those lands under WDNR management will mean that at least 4,000 acres (>50 percent of the lands) could be logged. Even when done in compliance with the restrictions mandated in the Lake Whatcom Landscape Plan, approximately 40 percent of those 4,000 acres would potentially be in various stages of revegetation at any given time using a 100-year harvest rotation schedule.

The soils would be unstable and more prone to erosion and landslides, greatly increasing the risk of more phosphorus loadings to the lake. The risk of landslides from logging activities in the watershed is not trivial, as evidenced by the catastrophic landslide in the Smith Creek tributary in the early 1980s that carried tons of soil as well as several houses into the lake.

Scientific studies confirm that any logging, as well as associated road-building, will greatly increase the risk of soil and phosphorus loadings to waterbodies. In a review of 22 scientific studies of landslides in forested areas compared to harvested (logged) areas in the Pacific Northwest, Heiken (1997) found that logged areas have landslide rates up to 20 times higher than forested areas.

Moreover, logged areas contributed eight times more soil due to erosion, and roads associated with logging activities exhibited landslide rates as much as 300 times higher than forested areas and caused soil transfer rates up to 200 times higher than forested areas. The argument that passive park and recreational activities in the watershed will do more harm to the lake than selective logging is not supported based on these and numerous other studies (Reid, 1993).

• Biological productivity is still increasing in the lake as a result of continued inputs of phosphorus and other nutrients.

• The unusually cold weather in spring and fall of last year helped to moderate the rate of water quality degradation in the lake.

• Warmer weather patterns that persist for several years will accelerate water quality degradation in the lake, as well as affect future quantities.

• Strategies to reduce phosphorus loading in the lake require using a combination of many different approaches including:

▲ Requiring all new developments to have zero discharge of stormwater runoff from the property,

▲ Involving every homeowner of existing developed properties in the watershed in infiltrating stormwater runoff on her/his property to prevent it from entering the lake,

▲ Trying new technologies to remove phosphorus from stormwater runoff,

▲ Continuing the Lake Whatcom Land Acquisition Program,

▲ Reconveying forestry lands for passive park use and recreation, and

▲ Being a good lake steward to protect and preserve our drinking water source for us and for future generations. §

• Heiken, D. 1997. Landslides and Clearcuts: What Does the Science Really Say? Umpqua Watersheds: Landslides Studies, Umpqua Watersheds, Inc, Available online at: http://www.umpqua-watersheds.org/local/landslides/slide_studies.html. 8 p.

• Matthews, R.A., M. Hilles, J. Vandersypen, R.J. Mitchell and G.B. Matthews. 2007. Lake Whatcom Monitoring Project 2005/2006 Final Report. Western Washington University, April 12, 1999. 496 p. Available online at http://www.ac.wwu.edu/~iws under Lake Studies — Lake Whatcom Online Reports.

• Matthews, R.A., M. Hilles, J. Vandersypen, R.J. Mitchell, and G.B. Matthews. 2008. Lake Whatcom Monitoring Project 2006/2007 Final Report. Institute for Watershed Studies, Western Washington University, Bellingham, WA, 401 p. Available online at http://www.ac.wwu.edu/~iws under Lake Studies — Lake Whatcom Online Reports.

• Paulson, A.J. 2004. Sources of Mercury in Sediments, Water, and Fish of the Lakes of Whatcom County, Washington. U.S. Department of Interior, U.S. Geological Survey Scientific Investigations Report 2004-5084, Reston, VA. 98 p.

• Pickett, P. and S. Hood. 2008. Lake Whatcom Watershed Total Phosphorus and Bacteria Total Maximum Daily Loads — Water Quality Findings. Publication No. 08-03-0xx, Draft — 4-21-08. Washington State Department of Ecology, Olympia, WA, 71 p.

• Reid, L.M. 1993. Research and cumulative watershed effects. Gen. Tech. Rep. PSW-GTR-141. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture; 118 p.

• Whatcom County. 2008. Draft Lake Whatcom Watershed Land Transactions, Memorandum of Agreement between Whatcom County and Washington State Department of Natural Resources. February 22, 2008. 10 p.

• WDOH (Washington State Department of Health). 2001. Fish Advisory: Mercury in Lake Whatcom Smallmouth Bass and Yellow Perch. Available online at: http://www.co.whatcom.wa.us/health/environmental/food_safety/fishadvisory.jsp.

• USEPA. 1986. Quality Criteria for Water 1986. United States Environmental Protection Agency, Office of Water, Regulations and Standards, Washington, D.C., EPA Publication 440/5-86-001. 477 p.