2001 Monitoring Reports
Section IV. Water Quality Survey
Introduction
This summary documents two full years of water quality monitoring for a segment of Coffee Creek located within the Coffee Creek Watershed Preserve (Figure 1). The creek drains a fairly small watershed of approximately 16 square miles. The purpose of the monitoring project was to characterize the water quality of Coffee Creek and provide baseline data for comparison as development occurs within the project site and watershed.
Materials and Methods
Samples were collected once per month from November 1999-December 2000 at eight sites within the Coffee Creek Watershed Conservancy Area (Figure 1). Early in 2001, the sampling scheme was revised to exclude three of the sampling locations that were considered redundant. Site 1 was shifted further west to sample Shooter Ditch just prior to its confluence with Coffee Creek. Site 2 on the mainstem of Coffee Creek was moved just upstream of the confluence of Shooter Ditch with Coffee Creek. Sites 4 and 5 were removed due to similarity with Site 6, and Site 7 was removed due to similarity with Site 8. For purposes of the current report and analysis, data collected in similar locations during the two sampling seasons (2000 and 2001) is compared. Data collected at Sites 1, 2, and 3 in 2000 are directly compared with 2001 data collected at Sites 1, 2, and 3 due to close proximity on the landscape. Site 6 sampled during 2000 is comparable to Site 4 sampled during 2001, and Site 8 from 2000 was labeled Site 5 during 2001.
Sampling dates, parameters measured, and detection limits are listed in Table 5. Data was analyzed by comparing concentrations of parameters through the year. Concentrations express the mass of a substance per unit volume, for example milligrams of total suspended solids per liter. Mass loading (kg/day) was calculated for each site for each date. Mass loading measures the quantity of a substance entering the creek at each of the five sampling sites per unit time. Loading is important when comparing among sites and among sampling dates because: 1) Flow can be highly variable; therefore, normalizing concentrations to flow eliminates variability. 2) Delivery of materials is important to consider. For example, a stream with high discharge but low pollutant concentration may deliver a larger portion of a pollutant to its receiving body than a stream with higher pollutant concentration but lower discharge. General precipitation data for Porter County was obtained from the Purdue Applied Meteorology Group's website and is displayed in Figure 17 ( http://shadow.agry.purdue.edu/sc.index.html ).
|
Sample Dates |
Parameter |
Parameter Detection Limit |
|
|
11/01/99 |
Conductivity | 10 umhos/cm | |
|
12/01/99 |
E. coli | 1 col/100ml | |
|
01/10/00 |
Nitrate-Nitrogen (NO3--N) | 0.05 mg/l | |
|
03/06/00 |
pH | ||
|
04/06/00 |
Total Suspended Solids | 2.0 mg/l | |
|
05/04/00 |
Ammonia-Nitrogen (NH3-N) | 0.01 mg/l | |
|
06/08/00 |
Total Kjeldahl Nitrogen (TKN) | 0.50 mg/l | |
|
07/05/00 |
Dissolved Oxygen (DO) | 0.10 mg/l | |
|
08/02/00 |
Total Phosphorus (TP) | 0.10 mg/l | |
|
09/12/00 |
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|
10/05/00 |
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|
11/09/00 |
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|
12/06/00 |
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|
03/23/01 |
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|
06/28/01 |
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|
09/10/01 |
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|
10/24/01 |
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|
12/12/01 |
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Figure 17.
Daily precipitation from March 2001 through December 2001 for
Porter County, Indiana. Arrows indicate sampling events. Data
source:
http://shadow.agry.purdue.edu/sc.index.html
Results and Discussion
Table 6 shows flow for each site by date. Sites 1 and 3 had very low flows. A beaver dam blocks Site 1 just upstream of the sampling location. Site 3 is a small stream and although it flows throughout the year, it drains only a small area and does not carry much water. The remaining three sites had higher discharge rates. Flows peaked during the October sampling due to nearly 4" of rain during the preceding days (Table 6).
|
Site |
|||||
|
Date |
1 |
2 |
3 |
4 (Site 6 in 2000) |
5 (Site 8 in 2000) |
|
11/4/1999 |
0.1 |
0.1 |
0.1 |
3.3 |
6.9 |
|
12/1/1999 |
0.1 |
** |
0.2 |
8.5 |
10.1 |
|
1/10/2000 |
0.44 |
** |
** |
10.9 |
10.2 |
|
2/1/2000 |
* |
* |
* |
* |
* |
|
3/6/2000 |
0.1 |
** |
0.3 |
14.8 |
16.3 |
|
4/6/2000 |
** |
** |
0.1 |
9.5 |
8.2 |
|
5/4/2000 |
** |
** |
0.5 |
9.8 |
7.7 |
|
6/8/2000 |
** |
** |
0.8 |
7.4 |
16.8 |
|
7/5/2000 |
** |
0.1 |
0.2 |
19.3 |
23.8 |
|
8/2/2000 |
** |
** |
** |
9.2 |
16.6 |
|
9/12/2000 |
3.8 |
** |
1.0 |
48.7 |
68.6 |
|
10/5/2000 |
** |
** |
0.1 |
14.6 |
20.2 |
|
11/9/2000 |
** |
** |
** |
7.1 |
17.7 |
|
12/6/2000 |
* |
* |
* |
19.6 |
19.0 |
|
3/23/2001 |
1.8 |
11.2 |
0.5 |
7.0 |
18.0 |
|
6/28/2001 |
0.6 |
5.3 |
0.1 |
7.5 |
9.4 |
|
9/10/2001 |
2.3 |
4.5 |
0.1 |
11.1 |
22.2 |
|
10/24/2001 |
1.3 |
7.3 |
0.6 |
21.7 |
24.0 |
|
12/12/2001 |
3.8 |
13.1 |
0.3 |
13.8 |
12.6 |
Table 6.
Discharge in cubic feet per second (cfs) for all sites by
sampling date for the 1999-2001 monitoring seasons. A single
asterisk (*) indicates that no sample was taken due to ice
coverage. A double asterisk (**) indicates that the water was
stagnant or not flowing.
Figure 18. pH values for Coffee Creek, November 1999-December 2001.
Figure 18 shows that Coffee
Creek was fairly alkaline, having pH values near 8. Dissolved
oxygen concentrations ranged between 7.3 and 14 mg/l. These
levels are conducive to cold-water fish, like salmonids, which
require higher oxygen levels than warm-water fish such as
bluegill or bass. Figures 19-23 display concentration and
loading data for two forms of nitrogen: nitrate-nitrogen (NO 3
- ) a dissolved, inorganic form of nitrogen and total Kjeldahl
nitrogen (TKN) an organic form of nitrogen which includes
ammonia and is found in plant and animal material. Nitrate
concentrations were near or below detectable levels for most
sites on most dates. Concentrations were well below Indiana
safe drinking water standards of 10 mg/l (per 327 IAC 2).
Typically, Site 3 had higher TKN concentrations than
concentrations measured at the other four sites. Site 3 also
had the lowest discharge of all of the sites. Increased organic
nitrogen concentrations could have been caused by a collection
of organic material undergoing decomposition. Total phosphorus
concentrations are not displayed because levels exceeded the
laboratory detection level of 0.10 mg/l on only one occasion
(Site 3, September 2001). Low nutrient levels usually
correspond with low productivity, which is typical of small,
"headwaters" streams like Coffee Creek. Unproductive streams
typically contain low quantities of organic matter. Scarce
litter keeps decomposition rates low and allows oxygen to
remain available for use by other aquatic life.
Figure 19. Nitrate-nitrogen concentration data for 1999-2001
water quality monitoring seasons.
Figure 20. Nitrate-nitrogen loading data for the 1999-2001
water quality monitoring seasons.
Figure 21. Total Kjeldahl nitrogen concentration data for the
1999-2001 water quality monitoring seasons.
Figure 22. Total Kjeldahl nitrogen loading data for the
1999-2001 water quality monitoring seasons.
Figures 23 and 24 portray total
suspended solids (TSS) data for the two monitoring years,
1999-2001. Suspended solid concentrations were low in Coffee
Creek Watershed streams even during storm events. TSS did not
reach levels deleterious to lithotrophic fish (90 mg/l) at any
point during the second year of sampling. TSS concentrations
were generally highest at Site 3. TSS loading increased between
Sites 4 and 5 suggesting that sediment erosion was occurring in
this area. Stabilization of the stream bank and other
restoration projects could potentially slow erosive processes
and reduce sedimentation of fish habitat.
Figure 23. Total suspended solids concentration data for the
1999-2001 water quality monitoring seasons.
Figure 24. Total suspended solids loading data for the
1999-2001 water quality monitoring seasons.
Summer (June) and early fall (September) E. coli
concentrations were elevated in Coffee Creek Watershed streams
during the 2001monitoring season (Figure 24). E. coli
concentrations at most sites were greater than 235 colonies/100
ml, the Indiana state standard for contact recreation. Contact
with stream water during summer months may present a health
risk based on the 2001 monitoring data. Potential sources of E.
coli contamination include failing or poorly sited septic
systems, manure spreading near stream banks, and feces of other
animals that may be introduced to the stream.
Figure 25. E. coli concentration for the 1999-2001 water quality monitoring season. The dashed line represents the Indiana state standard for recreational water bodies.