A Study of Sediment Contamination in Lake Macatawa
Phosphorus Resuspension Studies in the Lake Macatawa Watershed
Total Phosphorus Measurements in the Lake Macatawa Watershed
A Preliminary Survey of Water Quality Problems in Man-made Ponds within the Lake Macatawa Watershed
More research has been conducted in the watershed and is available in our watershed library at the MACC office please contact us at 616-395-2688 for access to these documents.
A Study of Sediment Contamination in Lake MacatawaGraham F. Peaslee
and
Natalie L. Hoogeveen, Dan G. Tobert, Meredith L. Praamsma, Lindsay A. Ellsworth, Julissa Pabon
Hope College
Rick R. Rediske
GVSU ¡V Annis Water Resources Institute
Three years ago, with the assistance of an EPA Great Lakes National Program Office grant, 15 sites in Lake Macatawa had sediment cores removed and tested for invertebrate toxicity, polyaromatic hydrocarbons (PAH) concentrations and heavy metal concentrations (Figure 1). This was the first lake sediment survey done in Lake Macatawa to examine the overall toxicity of the sediment. While the nutrient enrichment of Lake Macatawa was well known from the TMDL study, the historical industrialization of the watershed is not well known, at least in terms of its impact on sediment toxicity in the lake. The survey for organic compounds and heavy metals, combined with a gross toxicity measurement allowed us to report overall sediment health for the most common industrial pollutants.
Figure 1: The R/V Mudpuppy, which sampled the 15 sites shown in red on Lake Macatawa in early summer 2003. The only site with any unusual results is in yellow.
The results showed a relatively non-toxic lake sediment, and very low levels of organic contaminants as well as metal contaminants at 14 of the 15 sites sampled. This means that the Lake Macatawa sediment is relatively free of industrial contaminants, especially compared to similar West Michigan waterways to the north (e.g. White Lake) and south (e.g. Kalamazoo River). The only location (site 7) that showed slight toxicity (figure 2) also showed elevated levels of PAH¡¦s (figure 3) and lead (figure 4). The combination of these two contaminants in one location strongly suggest a small leaded fuel spill.
Figure 2: The results of toxicity testing on all 15 locations sampled on Lake Macatawa. Only site 7 shows evidence of slight toxicity, in that 10% fewer microorganisms survived in this sediment, compared to the other sites.
Figure 3: The concentration of PAHs found in all 15 locations sampled on Lake Macatawa. Only site 7 shows elevated levels above the EPA permissible levels.
Figure 4: The concentration of lead found in all 15 locations sampled on Lake Macatawa. Only site 7 shows elevated levels above the EPA permissible levels.
These data were not sufficiently worrisome to warrant further investigation, but we returned to this location last Summer to better characterize the extent of the sediment contamination near site 7. We were able to reproduce the elevated measurements of both lead and PAH¡¦s at this location, and at several adjacent locations (Figure 5).
Figure 5: Sampling sites added in Summer 2005 in red. The size of the red dot roughly indicates the amount of lead measured in each sample. The original EPA sample sites are shown in yellow. A nearby known leaking underground storage tank is shown as a blue star.
This research is continuing this year, with more detailed measurements of what types of PAH¡¦s are present, in addition to quantitative measurements of PAH¡¦s and lead and better spatial extent on the sampling points. It is important to measure the extent of this contamination for a baseline, so that in future years measurements can be made to determine whether this contaminant plume is actively expanding, or simply being buried with sediment over time.
Phosphorus Resuspension Studies in the Lake Macatawa WatershedGraham F. Peaslee
and
Heather M. Mentzer, Natalie L. Hoogeveen, Meredith L. Praamsma, Lindsay A. Ellsworth
Hope College
Rick Rediske, Alan Steinman
GVSU ¡V Annis Water Resources Institute
Over the past two years we have removed more than 20 sediment cores from Lake Macatawa (in four locations in three separate seasons) and incubated then in an environmental chamber on campus for 60 days to measure the amount of phosphorus that can resuspend from the sediment into the water column under various conditions. This study was designed to measure the total ¡§internal¡¨ phosphorus load compared to the enormous ¡§external¡¨ phosphorus load into Lake Macatawa that had already been reported with the TMDL study. If Lake Macatawa sediments do not bind phosphates well all year round, then certain anoxic water conditions that might occur during the summer months could lead to a significant loading of phosphorus from the sediment directly back into the water column above it. Evidence of this had been seen in several Florida lakes and by the GVSU researchers in Spring Lake and Mona Lake to the north.
Our procedure was to capture replicate 3¡¨ cores that were about 2 feet deep (Figure 1) and incubate them at environmental temperatures in an oxygenated environment in the laboratory for 30 days. Small aliquots of water were removed from the water column above the core periodically during this time period and sent to GVSU for phosphorus analysis. Then the cores were turned anoxic by bubbling nitrogen over them for another 30 days, and the water sampling was repeated during this phase.
Figure 1: A typical sediment core used in the phosphorus resuspension study.
Analysis continues on this project, but the preliminary results indicate several expected results and one unexpected result. Overall, since the Lake Macatawa sediments are rich in phosphorus from years of historical phosphate run-off, the sediment do resuspend some phosphorus into the water column under certain conditions. When the lake water is oxygenated, phosphorus tends to ¡§drop out¡¨ of the water column and add to the sediments, and when the lake water goes anoxic, a release of phosphorus was typically seen (Figure 2). This release of phosphorus was observed to increase strongly with ambient temperature, as might also be expected. We tested our cores at incubation temperatures between 10„aC and 25„aC (50 - 77„aF). However, compared to other lakes which have been studied by similar methods in the past, Lake Macatawa seems to demonstrate little phosphorus resuspension overall (Figure 3). This would be extremely good news for the on-going remediation efforts in the Lake Macatawa watershed, if it is true, as it means that once in the lake sediment, phosphorus rarely makes it back into a bioavailable form in the lake water.
Figure 2: Average total phosphorus measurements of the water column above three Lake Macatawa cores under oxygenated and deoxygenated conditions. The oxygenated cores tend to have decreasing total phosphorus levels with time, while the deoxygenated cores showed increasing total phosphorus levels with time. These cores were run at 10„aC.
Figure 3. A comparison of the preliminary total phosphorus release rates from Lake Macatawa sediment, compared to other lakes that have been studied by GVSU.
There are several possible explanations for this apparently low resuspension of phosphorus in Lake Macatawa. The first might be a measurement systematic error due to the fact these cores were oxygenated first for 30 days, and then turned anoxic. If anaerobic bacteria are heavily involved in the release of bound phosphates from the sediment, then this might have altered the environment sufficiently to lower all our release values. We are investigating this currently by running two more cores in parallel and series, to see if a difference is observed before we make our final report.
Another possibility is that Lake Macatawa is a relatively shallow lake, compared to nearby Spring Lake and Mona Lake. This means the sediments remain more oxygenated year round, and phosphorus bound to iron in the sediments might not release as easily . There is some evidence for this in a collection of published release rates for lake sediments from around the world (Figure 4). We should be able to resolve this interesting question within a few months.
Figure 4: A comparison of 8 lakes where total phosphorus release rate measurements have been made, as a function of their mean depth. Lake Macatawa, with an estimated mean depth of about 2.5 m is shown in blue. Mona Lake and Spring Lake have estimated mean depths of 4 and 6 m respectively.
Internal Phosphorus Loading Final Report AWRI
Internal Phosphorus Results AWRI
Total Phosphorus Measurements in the Lake Macatawa WatershedGraham F. Peaslee
and
Junu Shrestha, Kyle M. Ranta, Heather M. Mentzer, Natalie L. Hoogeveen,
Andrew J. Huisman, Robert J. Bartlett, Joseph Postma, Christopher W. Avery
We have had an active environmental chemistry group at Hope College studying various aspects of the Lake Macatawa Watershed for the past seven years. We have repeatedly taken surface water samples for total phosphorus measurements each summer, and in the early years we reproduced several of the MDEQ studies that demonstrated that most of
the phosphorus entering Lake Macatawa was inorganic orthophosphorus attached to sediment. Using colorimetric measurements, some of our first results showed how incredibly concentrated the phosphorus readings could be at some selected sites in the watershed (Figure 1).
Figure 1: Total orthophosphate measurements of three Fillmore Township sites that show readings that typically occurred shortly after a heavy rain event in small streams next to agricultural lands. Note that two years earlier, the TMDL study had measured an average level of phosphorus in Lake Macatawa at 127 ppb.
Upon further study, we have found a relatively strong correlation between the MDEQ measurements of phosphorus measurements in Lake Macatawa itself, and the total amount of precipitation that occurs in the early Spring months (April, May, June). These precipitation figures, taken from National Weather Service sources for the Holland area are only approximate, but they already show a clear correlation with measured phosphorus levels in Lake Macatawa (Figure 2). This indicates that sediment transport
Figure 2: Average phosphorus concentrations measured in Lake Macatawa by the MDEQ (in blue) plotted together with the spring rainfall amounts measured by the NWS (in red).
during heavy rain events plays a critical role in the delivery of phosphorus into Lake Macatawa. Also, since the TMDL study year occurred in the driest year of the subsequent 8 years, we suggest that the average value of 127 ppb that they measured in Lake Macatawa is probably an underestimate of the long-term phosphorus concentrations in the lake. Since hypereutrophic conditions exist for lakes with phosphorus levels above 50 ppb, even a value of 127 ppb seemed high at the time of the TMDL study, but in a wet year (2000) that followed, the average value in Lake Macatawa exceeded 450 ppb! Clearly Lake Macatawa belongs in a class to itself among Michigan lakes, and we decided to pursue further research on the lake and its watershed in order to better understand its unique features.
A Preliminary Survey of Water Quality Problems in Man-made Ponds within the Lake Macatawa Watershed Graham F. Peaslee and K. Greg Murray
and
Ann Gisinger, Meredith L. Praamsma, Lindsay A. Ellsworth
Hope College
Extensive water quality surveys have been conducted of the Great Lakes and most of the natural waterways that feed into them. However, over the past two decades there has been a growth of smaller man-made ponds, usually as part of residential development, and for the most part these waterways have not be well studied. Usually these waterways are a shared resource between many land-owners or are maintained by a land-owner association and anecdotal evidence exists of many common water quality problems, such as excessive algae or aquatic plant growth, or heavy siltation with organic detritus. These problems have given rise to an entirely new form of commercial enterprise, the ¡§lake management¡¨ companies that are often hired to apply herbicides and pesticides to solve the problems found in these smaller inland ponds. The purpose of this study is to conduct a first survey of the small ponds in the Macatawa watershed, and to assess the water quality in each as a function of several geophysical and ecological variables.
Our research began last summer on this project, and using geographical information systems to interpret aerial photographs, various calculations were performed to initially identify a subset of about 20 ponds to study in the Lake Macatawa watershed. The man-made ponds were chosen to be of similar sizes, similar creation dates and in one geographical area (circled in red in Figure 1) for convenience to study.
Figure 1: The Lake Macatawa watershed with the area where the preliminary pond study was conducted circled in red. About 18 manmade ponds in this area were compared with three more natural ponds at the Outdoor Discovery Center.
From each pond, sediment was collected for analysis of phosphate and copper levels using a microwave digestion and an Inductively Coupled Plasma Spectrometer. Copper was analyzed due to the use of copper sulfate and chelated copper by lake management companies to treat ponds. Phosphates and nitrates are usually the limiting factors for growth in ponds and are often attributed to fertilizer runoff. Nitrates were analyzed from water samples using an ion selective probe. Identification of invertebrates, aquatic plants, and algae taken from each pond were statistically analyzed for diversity and similarity between natural and artificial ponds.
The results from our first summer of research are very preliminary, but indicate that water ¡§treatment¡¨ effects on these small ponds are quite measurable. All ponds that had ever received copper or chelated copper treatment for algae growth displayed significantly enhanced levels of copper in the pond sediment. This was true even for ponds that hadn¡¦t received such treatment in over three years. We also found some evidence at one location that copper-enriched sediment had escaped the pond where it was applied and had been transported into an adjacent natural waterway. Given the toxicity of copper and the ubiquity of its use to treat algae-infested ponds, this may well be an emerging water quality problem for the entire watershed. We also observed statistical significant algal and invertebrate species richness and species diversity differences between chemically treated, biologically treated and natural ponds. We are applying for funding to continue this research for the next few years.
Figure 2: Julissa Pabon (U. Puerto Rico), Lindsay Ellsworth (Hope College), Ann Gisenger (U. Rochester), Graham Peaslee and Greg Murray sampling sediment from a man-made pond in the Macatawa Watershed, Summer 2005.
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