Dr. Robin Matthews, Director Institute for Watershed Studies Huxley College of the Environment
Western Washington University
Lake Whatcom is
comprised of 2 small, shallow basins and one large, deep basin
Each shallow basin is only
~20 m (60 ft) deep and contains about 2% of the total water in the lake
Site 1 Basin 1 Site 2
Basin 2
Bloedel/ Donovan
Park
Basin 3 is over 100 m (300 ft) deep and contains 96% of the total water in the lake All of the major tributaries to the lake flow into basin 3, including water diverted from the Middle Fork of the Nooksack River
Site 3 Basin 3 (north end)
Site 4 Basin 3 (south end)
Sudden Valley
Lake Whatcom Monitoring Objectives
Conduct long-term lake and stream monitoring
Emphasis on lake and storm event monitoring
→ Silver Beach Creek 2009-2012
→ Anderson, Austin, and Brannian Creeks 2013-2015
Tributaries in alternate years
Collect stream hydrologic data
Annual hydrographs for Austin and Smith Creeks
Sampling Parameters
Lake, Tributaries, and Storm Event Sampling
Alkalinity Conductivity Dissolved oxygen
pH Temperature Nutrients (N/P)
Lake Only
Chlorophyll Turbidity Plankton
Secchi depth T. organic carbon* Hydrogen sulfide*
Tributaries and Storm Events Only T. suspended solids
Lake is cold and unstratified; water column mixes from surface to bottom … even basin 3 (100 m)
Temperature is nearly uniform from surface to bottom
Dissolved oxygen and most other compounds are nearly uniform from surface to bottom
Site 1 - December 2012
Depth from surface (m)
0 5 10 15
-20-15-10-50
Winter Water Quality in Lake Whatcom
0 5 10 15 20 25
-20-15-10-50
Lake becomes stratified into a warm surface layer
(epilimnion) and cold
bottom layer (hypolimnion) Once stratified, wind can’t mix the entire water column In parts of the lake (Sites 1- 2), oxygen is depleted in the hypolimnion as bacteria decompose organic matter (dead algae, leaf fragments, etc.)
Site 1 - July 2013
Depth from surface (m) epilimnion
(metalimnion)
hypolimnion
Summer Water Quality in Lake Whatcom
Dissolved Oxygen in Lakes
The primary source of dissolved oxygen in lakes is from the atmosphere
Algae produce oxygen during photosynthesis (daytime) but consume oxygen at night
When the lake stratifies, oxygen levels near the surface remain high because of contact with the atmosphere
Water near the bottom is isolated from the atmosphere during stratification, so no additional oxygen is introduced until late
0 5 10 15 20
-20-15-10-50
0 5 10 15 20
-80-400
1 km 1 mile
Basins 1-2 have different oxygen profiles than basin 3
Site 1 - Oct 2013
Site 4 - Oct 2013
Depth (m)
Oxygen Temperature
Depth (m)
0 5 10 15
-20-15-10-50 May
June July Aug Sept
At Sites 1-2
hypolimnetic oxygen depletion begins after the lake stratifies
This may start as early as April* but usually begins in May or early June, depending on weather conditions
*2015 – may have very early stratification
Site 1 - May 2013
Depth from surface (m)
0 5 10 15
-20-15-10-50 May
June July Aug Sept
An oxygen sag typically develops by June
By June 2013,
oxygen levels were 4.5 mg/L lower at the bottom
compared to the surface
Surface oxygen levels fall slightly at the surface because the water is warmer
warm water holds less oxygen than cold water
Site 1 - May and June 2013
Depth from surface (m)
0 5 10 15
-20-15-10-50 May
June July Aug Sept
As the summer progresses, the oxygen depletion in the hypolimnion
becomes increasingly evident
The bulge between 5- 10 meters is a
metalimnetic oxygen maximum caused by bands of algae
Site 1 – May to July 2013
Depth from surface (m)
metalimnion oxygen maximum
caused by algae
0 5 10 15
-20-15-10-50 May
June July Aug Sept
By August, there is almost no oxygen in the hypolimnion
Once oxygen levels fall below ~2 mg/L, the only aquatic
organisms that thrive are anaerobic
bacteria
Site 1 – May to August 2013
Depth from surface (m)
0 5 10 15
-20-15-10-50 May
June July Aug Sept
The September
hypolimnion oxygen concentrations
resemble August because additional oxygen won’t be introduced until destratification
(Oct/Nov at Sites 1-2; Dec/Jan at Sites 3-4)
Site 1 - May- to September 2013
Depth from surface (m)
Depth from surface (m)
12 meters
0 5 10 15
-20-15-10-50 May
June July Aug Sept
The rate of hypolimnetic oxygen consumption is increasing
Depth from surface (m)
12 meters
0 5 10 15
-20-15-10-50 May
June July Aug Sept
14 meter depth
July (p-value ≤0.001) Aug (p-value ≤0.001)
1990 1995 2000 2005 2010 2015 6
4
2
0
Dissolved Oxygen at 14 meters, 1989 - 2014
Dissolved oxygen (mg/L)
July (p-value ≤0.001) Aug (p-value ≤0.001)
1990 1995 2000 2005 2010 2015 6
4
2
0
Dissolved Oxygen at 14 meters, 1989 - 2014
Dissolved Oxygen (mg/L)
July (p-value ≤0.001) Aug (p-value ≤0.001)
1990 1995 2000 2005 2010 2015 6
4
2
0
Dissolved Oxygen at 14 meters, 1989 - 2014
Dissolved Oxygen (mg/L)
Water Quality Problems Associated With
Low Dissolved Oxygen
Loss of aquatic habitat
fish need at least 4-6 mg/L dissolved oxygen
Release of nutrients and other compounds from the
sediments
Dissolved metals, methylated mercury, hydrogen sulfide Phosphorus
Increased Phosphorus
Availability in Lake Whatcom = More Algae in Lake Whatcom
New internal sources Phosphorus released from
sediments under low
Increased Phosphorus
Availability in Lake Whatcom = More Algae in Lake Whatcom
New external sources Phosphorus transported on
soil particles in surface New internal sources
Phosphorus released from sediments under low
Storm Water Monitoring
Samples collected during storms of ≥1 cm in 24-hr
At least 7 samples must be collected during rising and falling portion of the storm hydrograph
Samples analyzed for total suspended solids and nutrients
2010-2012: Silver Beach Creek (24 storm events)
2013-2015: Austin, Anderson, Brannian Creeks (14 storm events)
2013-2014: Smith Creek (22 storm events; Beeler M.S. thesis –
3.54.04.55.05.56.0
(02/21 00:00) (02/22 00:00) (02/23 00:00)
Silver Beach Creek Storm Water Monitoring (Event #23: Feb 20-23, 2012)
Flow (cfs)
Feb 21 Feb 22 Feb 23
Rising portion of hydrograph
Falling portion of hydrograph
Silver Beach Creek Storm Water Monitoring (Event #23: Feb 20-23, 2012)
3.54.55.5
0 50 100 150 200 250 300 350
Flow (cfs)
TSS (mg/L) 4.55.5
100 200 300 400 500
Flow (cfs)
TP(µg−PL)
Points represent discrete samples
Points represent discrete samples
Silver Beach Creek Storm Water Monitoring (Event #23: Feb 20-23, 2012)
3.54.55.5
0 50 100 150 200 250 300 350
Flow (cfs)
TSS (mg/L) 4.55.5
100 200 300 400 500
Flow (cfs)
TP(µg−PL)
Points represent discrete samples
Points represent discrete samples Sediment (TSS) that is transported in storm runoff carries high
concentrations of phosphorus, most of which is attached to particles
Storm Water Monitoring
The results will be used to estimate whether City/County
are meeting TMDL phosphorus reduction goals
Continuing lake water quality monitoring will serve as the
ultimate test of whether phosphorus reduction has
reduced algae in the lake and improved hypolimnetic
oxygen concentrations
Need to have realistic time goals for recovery!
Relationship between Phosphorus in
Storm Runoff and Lake Whatcom Algae
Lake Whatcom algae sample
Although phosphorus enters Lake Whatcom attached to soil particles, it doesn’t necessarily stay attached!
Determining biological available phosphorus in storm water entering Lake Whatcom, WA using the dual
Although phosphorus enters Lake Whatcom attached to soil particles, it doesn’t necessarily stay attached!
Storm water containing phosphorus
attached to soil particles P-starved algae release enzymes
that release soluble phosphorus from soil particles
Determining biological available phosphorus in storm water entering Lake Whatcom, WA using the dual
1995 2000 2005 2010
1234567
Site 1
Chl (µgL)
tau = 0.578 p-value <0.001
1995 2000 2005 2010
1234567
Site 2
Chl (µgL)
tau = 0.644 p-value <0.0001
1995 2000 2005 2010
1234567
Site 3
Chl (µgL)
tau = 0.686 p-value <0.0001
1995 2000 2005 2010
1234567
Site 4
Chl (µgL)
tau = 0.695 p-value <0.0001
Increasing Chlorophyll in Lake Whatcom
Increasing Chlorophyll at Site 4 in Lake Whatcom
1995 2000 2005 2010
12345
Chl (µgL)
Chlorophyll range prior to 2000
Increasing Chlorophyll at Site 4 in Lake Whatcom
1995 2000 2005 2010
12345
Chl (µgL)
Chlorophyll range prior to 2000
Increasing Chlorophyll at Site 4 in Lake Whatcom
1995 2000 2005 2010
12345
Chl (µgL)
Chlorophyll range prior to 2000
Water Quality Problems Associated With
High Concentrations of Algae
Positive feedback loop between algae and phosphorus
Algae remove phosphorus from soil, which causes algal growth in the photic zone rather than loss of phosphorus to sediments or outflow (Whatcom Creek)
Decomposing algae release phosphorus, which causes more algal growth Some lakes have toxic algae blooms (currently not a problem in Whatcom) Increased drinking water treatment costs
Disinfection byproducts Taste and odor problems
Increasing THMs in Bellingham’s Treated Drinking Water
Qtr 1-4 Adj r2 = 0.292 ρ ≤ 0.0001
Qtr 3 (July-Sept) Adj r2 = 0.529 ρ ≤ 0.0001
0.010.030.05
TTHMs (mg/L)
11/91 05/97 11/02 05/08 10/13
adj-r^2 = 0.283 p-value <0.0001
0.010.030.05
TTHMs (mg/L)
11/91 05/97 11/02 05/08 10/13
adj-r^2 = 0.476 p-value <0.0001
Phase II (more sites
Jan – Dec (Qtr 1-4)
Jul– Sept (Qtr 3)
In 2009, summer algal blooms caused water filtration to slow, resulting in mandatory limits on water use
Slow filtration continues to be a problem during summer (less severe than in 2009)
Cyanobacteria (blue green algae) and diatoms are associated with the slow filtration
The algae are not toxic, but probably contribute to the increasing THMs and other water treatment problems
Source Water Pretreatment
The TMDL is designed to reduce algae concentrations in
Lake Whatcom
But the estimated time for this process will be decades!
The City needs to prevent summer water shortages,
which will most likely use source water pretreatment
Source water pretreatment will not be a substitute for
cleaning up the lake (legal obligation)
Source Water Pretreatment
Dissolved Air Floatation
Algae removed as sludge
Photo provided by City of
Bellingham and
Effectiveness of DAF
Date
Pre-DAF Algae
(cells/mL)
Post-DAF Algae
(cells/mL)
Pct.
Reduction
Chlorophyll Pct.
Reduction
Aug 15, 2011 4,636 576 88 85
Aug 30, 2011 11,350 1,225 89 89
Sept 15, 2011 12,368 877 93 87
Pre- and post-DAF algae and chlorophyll samples collected approximately daily (Aug 10 – Sept 15)
Where are we now?
Lake Whatcom Annual Report summarizes the current
conditions
Hypolimnetic oxygen levels still low at Site 1
Storm runoff carries increased concentrations of sediment and phosphorus into the lake
Chlorophyll concentrations (and algal counts) still high throughout the lake
Where are we now?
Lake Whatcom Annual Report summarizes the current
conditions
Hypolimnetic oxygen levels still low at Site 1
→ We can’t do much about this directly, but it should improve if the amount of algae in the lake can be reduced
Where are we now?
Lake Whatcom Annual Report summarizes the current
conditions
Storm runoff carries increased concentrations of sediment and phosphorus into the lake
→ The TMDL is designed to reduce phosphorus loading from the watershed
→ This will ultimately reduce the amount of algae in the lake, which will help protect Lake Whatcom as a recreational and drinking
Where are we now?
Lake Whatcom Annual Report summarizes the current
conditions
Chlorophyll concentrations (and algal counts) still high throughout the lake
→ This will improve (slowly) if we reduce the amount of phosphorus entering the lake
→ To address current water quantity requirements, source water pretreatment may be needed
Thanks!
Mike Hilles Joan Vandersypen
Marilyn Desmul Dr. Robert Mitchell Dr. Geoffrey Matthews
undergraduate and graduate students
