SAMPLING
Determining what pollutants are making it into streams and
groundwater plays an important role in helping us identify which human
activities are causing significant problems. As part of this project
the Department of Ecology has been able to conduct several types of
sampling in three different areas.
Lake
Whatcom/Whatcom Creek
Padden Creek
Squalicum Creek
LAKE WHATCOM / WHATCOM CREEK
The Washington State Department of Ecology conducted a screening-level
survey of contaminants in the Lake Whatcom and Whatcom Creek watersheds
during 1998. Lake Whatcom is the sole drinking water source for more than
65,000 Whatcom County residents, including the city of Bellingham. Sampling included water
collected from six streams or storm drains during spring and fall
rainstorms; sediments from the same six stream/storm drain sites as well
as from three sites in Lake Whatcom; and tissues from several species of
fish found in Lake Whatcom and Whatcom Creek. Sites were assessed for a
variety of contaminants including fecal coliform bacteria, nutrients,
metals, total petroleum hydrocarbons, semivolatile organics (PAHs,
phthalates, phenols), pesticides, and PCBs.
Results indicated that while some chemicals were present at levels of
concern, overall contamination was low-to-moderate and similar to other
urban areas of the Puget Sound basin. Contaminants of concern in water and
sediments at one or more sites include fecal coliform bacteria, copper,
zinc, mercury, bis(2-ethylhexyl)phthalate, butylbenzylphthalate,
di-n-octylphthalate, benzo(a)pyrene, benzofluoranthenes, chrysene,
dibenzo(a,h)anthracene, indeno(1,2,3-c,d)pyrene, chlorpyrifos, diazinon,
malathion, and pentachlorophenol. Mercury was elevated in one sample of
smallmouth bass from Lake Whatcom. A number of chlorinated pesticides and
PCBs were found in fish at low concentrations, although PCBs exceeded
National Toxics Rule criteria.
The 1998 sampling report
raised human health concerns about mercury contamination of Lake
Whatcom fish. To address these concerns, Ecology, Washington
Department of Fish and Wildlife (WDFW), Washington State Department of
Health (DOH), and Whatcom County Health and Human Services Department
conducted a follow-up study of mercury concentrations in edible fish
in 2000
.
The goal of the study was to help determine if consumers of Lake Whatcom
fish are at risk from mercury exposure.
Sampling revealed that mercury concentrations were much higher in
smallmouth bass (Micropterus dolomieu) compared to yellow perch (Perca
flavescens), kokanee (Oncorhynchus nerka), pumpkinseed (Lepomis gibbosus),
cutthroat trout (Oncorhynchus clarki), brown bullhead (Ameiurus
nebulosus), and signal crayfish (Pacifastacus leniusculus).
Concentrations were positively correlated with length and age in
smallmouth bass, and to a lesser extent in yellow perch and Basin 2
signal crayfish, but no such relationship was seen in other species. The
overall mercury concentration in smallmouth bass averaged 0.49 ug/g (wet
weight), and the maximum concentration was 1.84 ug/g. Mean mercury
concentrations in other species were generally 0.05 - 0.20 ug/g. All
species from the southern Basin 3 had more mercury on average compared
to their counterparts from the northern Basins 1 and 2, regardless of
average size or age. However, there was no consistent direction in
mercury concentrations between samples from Basin 1 and Basin 2.
The Washington State Department of Health will use these data to
develop a health risk assessment for Lake Whatcom, as a separate
document. The Washington Department of Fish and Wildlife will assess the
potential impact of mercury on fish health, also as a separate document.
Since 13 of the samples exceeded the EPA National Toxics Rule human
health criterion of 0.825 ug/g, the Washington State Department of
Ecology should add Lake Whatcom to the Section 303(d) list for mercury
in tissue. Other recommendations are to investigate possible mercury
sources to Lake Whatcom and determine if lake or watershed
characteristics promote enhanced mercury uptake and accumulation by
fish.
PADDEN CREEK
Extensive sampling was conducted in Padden Creek between 2000-2003 in
conjunction with the Residential Pledge education efforts taking place
there. Ecology made funding available to Western Washington
University to simultaneously conduct macroinvertebrate sampling and
sampling for conventional water quality parameters, such as temperature
and dissolved oxygen.
Pesticide levels in water were characterized at four sites in Padden
Creek from April to June in 2001 and in 2003. The pesticide monitoring was
part of a larger effort by the Department of Ecology, Western Washington
University, and the City of Bellingham to evaluate water quality
conditions in the Padden Creek basin and to identify areas of concern. The
results of this study were used to educate the public and intensify
efforts in preventing pollution from residential applications.
Nineteen of 111 pesticides were detected among four sample sites during
six sampling events, four in 2001 and two in 2003. The 19 pesticides are
as follows:
• Fourteen herbicides: dichlobenil, diuron, MCPP (mecoprop), 2,4-D,
trichlopyr, pentachlorophenol, prometon, dicamba, simazine, MCPA, lenacil,
terbuthylazine, atrazine, and bromoxynil.
• Two herbicide breakdown products: 2,3,4,6-tetrachloropheno, and
2,6-dichlorobenzamide.
• Two fungicides: chlorothalonil (daconil) and 4-nitrophenol, a breakdown
product.
• One insecticide: diazinon. This was detected only during the 2001
sampling events.
Concentrations of pesticides detected in Padden Creek were low, with most
being at or slightly above detection limits. Two compounds, diazinon and
chlorothalonil, exceeded criteria for the protection of aquatic life
during the 2001 sampling events.
SQUALICUM CREEK
Between November 2002 and June 2003, the WA State Department of Ecology
conducted water and sediment sampling
in the Squalicum Creek watershed. The study sought to identify and
prioritize pollution sources and chemicals of concern in the watershed.
In the water, two of the pesticides detected and two of the metals
exceeded water quality criteria for the protection of aquatic life. In
the sediments, five semi-volatile organic compounds (SVOCs) and zinc
were found at levels exceeding recommendations for the protection of
aquatic life.
