Sentinel Lakes Program: Sentinel Lakes Program: Water quality monitoring Water quality monitoring

and assessmentand assessment

Steve Heiskary,Steve Heiskary,Research Scientist IIIResearch Scientist III

Environmental Analysis and Outcomes DivisionEnvironmental Analysis and Outcomes DivisionMinnesota Pollution Control AgencyMinnesota Pollution Control Agency

OutlineOutline

Lake assessment approachLake assessment approach What do we know about these lakes?What do we know about these lakes? Data analysis examples – variability and Data analysis examples – variability and

trends;trends; Plan for 2008-2009;Plan for 2008-2009; Collaboration with MDNR staff on Collaboration with MDNR staff on

reportingreporting SummarySummary

Proposed Sentinel Lakes: MPCA data & reporting summary

DOW Area Fisheries NameArea

Acres

Max Depth

(ft) P-levelSed. Core

Years of CLMP

Mean Secchi

(m)Years of

TPMean TP (mg/L)

LAP Report type & date Special studies

1014200 Aitkin Hill 907 48 high N 12 3.3 2 0.033 LAP 199415001000 Bemidji Elk 305 93 med N 10 3.9 1 0.031

18038600 Brainerd Red_Sand 516 23 med Y 6 3.2 3 0.028 CLMP+ 2002shallow lakes of WC MN

44004500 Detroit_Lakes Snider 632 29 low N 9 3.1 0

2000400 East_metro Peltier 465 18 high Y 31 0.9 23 0.286TMDL - P 2007 & sed. Core

21005700 Glenwood Carlos 2598 163 med N 31 5.6 22 0.021reference CHF; TMDL hg

16004900 Grand_Marais Trout 257 77 low N 7 7.6 6 0.012 CLMP+ 2004 reference NLF

16008900 Grand_Marais Northern Light 433 8 low N 0 013002700 Hinckley South_Center 898 109 high N 19 1.3 6 0.066 TMDL - P

47004900 Hutchinson Belle 856 25 high N 9 1.3 1 0.05969075700 International_FallsNet 108 18 high N 0 0 TMDL - Hg

69081000 International_FallsElephant 724 30 high N 3 1.8 049014000 Little_Falls Cedar 243 88 low N 13 3.3 2 0.02973003700 Montrose Pearl 746 17 low N 9 1.7 5 0.036 LAP 19976000200 Ortonville Artichoke 1964 16 high N 1 1.3 1 0.420 reference NGP

29025000 Park_Rapids Portage 412 17 high N 11 1.1 10 0.055 TMDL - P

34003200 Spicer Carrie 81 26 low N 3 1.0 069000400 Tower White_Iron 3238 47 med N 15 1.6 5 0.025 LAP 1996 TMDL - Hg

69025400 Tower Bearhead 674 46 med N 1 3.5 1 0.01411041300 Walker Ten_Mile 4669 208 low N 18 5.5 5 0.017 LAP 19917004400 Waterville Madison 1439 59 high N 16 0.9 8 0.100 LAP 200681000300 Waterville St_Olaf 99 33 med N 15 1.6 3 0.034 reference WCP

41008900 Windom Shaokotan 994 10 med Y 12 1.3 10 0.193 Status 2000

Shallow lakes of SW MN & TMDL - P 2007

83004300 Windom St_James 221 16 low N 4 1.0 1 0.074 LAP 1990

Sentinel Lakes Baseline Monitoring effort

•Split effort between summers of 2008 and 2009 (need to coordinate with other MPCA monitoring priorities);

•Anticipate baseline reports for 2008 lakes ready by spring 2009 and 2009 lakes by 2010;

•MPCA staff take lead in monitoring and report writing;

•Monitoring coordinated with area fisheries office and other local partners as appropriate;

Trends and Inter-annual VariabilityTrends and Inter-annual Variability

Provide some simple analysis of trends Provide some simple analysis of trends and variability in trophic status for select and variability in trophic status for select lakes;lakes;

Note the need for good quality data & Note the need for good quality data & potential problems when mixing data from potential problems when mixing data from several laboratories;several laboratories;

Example of sediment-diatom inferred TP Example of sediment-diatom inferred TP as a basis for assessing trendsas a basis for assessing trends

Hill Lake (North & South Bay) Summer-mean Secchi Depth

R2 = 0.64

0

1

2

3

4

5

6

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

me

ters

Hill (North Basin) Hill (South Basin) Linear (Hill (North Basin))

Hill Lake, Aitkin County. Example of apparent trend (total record) & variability (recent record). Large break in record. Transparency consistently lower in South Basin.

Lake Peltier – Rice Creek Chain: Anoka County.

No trends & modest variability over time, ~0.24 m on average (26% of long-term average)

Peltier Summer-mean Secchi Depth. Long-term mean noted

0.0

0.5

1.0

1.5

2.0

2.5

3.0

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

me

ters

Peltier Summer-mean Total Phosphorus

R2 = 0.07

0

0.1

0.2

0.3

0.4

0.5

0.6

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

mg

/L

Lake Carlos Summer-mean Total Phosphorus

R2 = 0.0303

0

0.01

0.02

0.03

0.04

0.05

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

ug

/LLake Carlos – Douglas Co.: Assessing trends & year-to-year variability:

No trend in TP, however variability is high. Is this real or a function of laboratory detection limits, multiple labs, outliers???

Portage Lake Secchi Depth

R2 = 0.14

0

1

2

3

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

met

ers

Portage Lake – Hubbard County:

Increase in TP & decline in Secchi in recent years

Portage Lake Summer-mean Total Phosphorus

R2 = 0.39

0

0.01

0.02

0.03

0.04

0.05

0.06

0.07

0.08

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

mg

/L

St. Olaf Lake Summer-mean Secchi

R2 = 0.0023

0

0.5

1

1.5

2

2.5

3

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

met

ers

St. Olaf Secchi residuals

-1.5

-1

-0.5

0

0.5

1

1973

1975

1977

1979

1981

1983

1985

1987

1989

1991

1993

1995

1997

1999

2001

2003

2005

2007

year

Sec

chi

(m)

St. Olaf Lake – Waseca County: High variability in Secchi for a small lake – 23% on average (typical 10-20%).

[Residuals are long-term mean- annual mean.]

Shaokatan (Lincoln) Diatom-inferred ( DI-P) & Observed (Obs.-P)

0

50

100

150

200

250

300

1750 1800 1989 1991 1992 1993 1994 1999 2000 2001 2002 2003

TP

pp

b

DI-P Obs.-P

Lake Shaokatan, Lincoln County:

Use of sediment cores & diatom reconstruction of TP

LAKE ASSESSMENT PROGRAM COOPERATIVE WORK PLAN

The following is a general work plan for this cooperative program. General work tasks and the group responsible for implementing the work tasks are briefly identified in this outline. Group abbreviations are: Minnesota Pollution Control Agency (MPCA); Lake Association or Local Unit (LA); Soil and Water Conservation District (SWCD) and Department of Natural Resources (DNR). This work plan may be adjusted according to MPCA and LA needs and capabilities. I. Citizen Lake Monitoring Program (participation is required) (LA)

- Weekly measures June to September at 1-2 stations.

II. Water chemistry analysis including nutrients, chlorophyll a, solids, pH, and color, plus a depth profile of oxygen and temperature

- Sample collection 1-2 stations 4-5 times/year (MPCA) and may include (LA). - Sample analysis (MPCA). - Data entry into STORET (MPCA).

III. Lake/Watershed Analysis - Determine lake volume (MPCA). - Define watershed (map) (LA assisted by SWCD or MPCA). - Identify all tributaries (in/out), storm sewers, agricultural tiles, etc., to the lake and map (LA). - Estimate land use composition in watershed (seek assistance SWCD). - Summary of fisheries and lake level measurements (DNR). - Assess number of homes around lake noting status (year round or seasonal) and waste disposal system (conduct septic system survey using questionnaire) (LA). - Compile a history of significant events / activities which have occurred around the lake,

watershed, or with the association (LA).

IV. Reporting A report will be drafted for each lake by the MPCA with assistance from study cooperators. This report will not serve as a diagnostic - feasibility study (e.g., Clean Water Partnership Phase I) for the lake, but will provide basic information regarding the lake and its watershed. The following items will be included in this report: - A summary/analysis of water chemistry, fisheries, and physical data. - Assessment of trophic status and trends and comparison with other lakes in the same ecoregion. - Map of lake and watershed identifying tributaries, etc., plus basic morphometric data. - Summary of land use in watershed. - Recommendations for lake water quality protection or improvement.

Sentinel Lakes additions:

• April-October, monthly

•Add cations and anions

•Work with Fisheries for up to date characterization of the fisheries & management;

•Work with Waters to describe water level record & trends;

•Macrophyte assessment?

•Trends: Secchi, TP & chl-a based on existing data, characterize variability;

•Modeling – MINLEAP & BATHTUB as appropriate

•Provide recommendations for frequency of monitoring & other data needs for lake.

SummarySummary Reviewed proposed Sentinel lakes & data availability for each.

Lakes selected range from Carlos and Peltier with data collected over the course 20-30 years to Net & Northern Light for which we have no data – Implications as we move forward?

Trend analysis will require extensive attention to quality assurance of data & ideally a single laboratory will be used for this work;

MPCA (Lakes & Streams Unit) proposes to sample each of the sentinel lakes over the course of one open-water season (April – October) during 2008 – 2009;

We will integrate this work with our projected (mandated) monitoring activities and with existing budget & staff;

We will write LAP-type reports that will serve to provide a baseline for each of the lakes;

These reports will provide a sound basis for deciding the frequency & intensity of future monitoring, which candidates may be best for more detailed analysis, and should serve to help shape future proposals for the Sentinel Lakes program.

Successful implementation of the Sentinel Lakes program will require having a clear vision of purpose, communicating that vision and developing extensive partnerships.