李玖哲好听的歌25 April 2007 Drinking Water Taste and Odor Workgroup meeting. Minutes by Debbie Baker, CPCB.
Attendees:
Sam Atherton, PWWSO#4 (Bill Hill Reservoir)
Deb Baker, KWO Ed Carney, KDHE
Debbie Baker, CPCB Jason Beury, CPCB
Dave Brewer, City of Lawrence Jerry deNoyelles, KBS
Andy Dzialowski, KBS Jennifer Graham, USGS
Don Huggins, CPCB Mark Jakubauskas, KBS夏天的微笑
Terry Lyons, COE Tom Lowe, KWO
Steve Randtke, KU Val Smith, KU
Shari Stamer, City of Lawrence Andy Ziegler, USGS
Andy Dzialowski briefed the group on the CPCB/KBS efforts to date:
-Database of previously collected data completed
-Reservoir sampling completed
-Model development currently taking place
-Project completion date is June 1, 2007
Regression models are being developed to predict geosmin concentrations from water quality data. The goal of the models is to determine if water quality variables, which are less expensive and easier to collect, can be used to estimate geosmin concentrations. These relationships between geosmin and water quality variables can then be used to make treatment decisions.
Predictive Models:
A universal model was developed predicting geosmin concentrations from water quality variables using data collected from four reservoirs: Big Hill, Clinton, Cheney and Marion. Data from all zones of the reservoirs (main basin, transition zone, and riverine zone) were used in the universal model. Data from Gardner Lake was excluded because taste and odor events were rare.
A single universal model was developed between PO4 (the amount of dissolved phosphorus available in the water column for algal uptake) and geosmin that explained ~36% of the variation in geosmin concentrations.
-Val pointed out that the negative relationship between geosmin and PO4 might have resulted from changes in phosphorus limitation. Under P limitation, algal cells may have extra nitrogen in their cells, which they can then use to produce N-rich geosmin.
-Jerry pointed out that the negative relationship between geosmin and PO陈冠希4 might have resulted from algae using the available PO4, which resulted in a bloom and resulting geosmin production.
A multiple variable model for all of the reservoirs combined was discussed.
-Andy Z. cautioned about using temperature as a variable in predictive models because of diurnal changes.
Models for each individual reservoir were presented.
A single variable model, using %pump it 黑眼豆豆Aphanizomenon (based on biomass, µm3/m), explained 87% of the variation in geosmin in Big Hill.梁静茹经典歌词
-It was pointed out that Big Hill is unique for Kansas in that it has relatively low nutrient concentrations.
-Sam asked how recent rains would affect T&O events in Big Hill
jita-Val answered that it might increase the flushing rate, but that it would also most likely bring nutrients into the reservoir.
-Jerry pointed out that Big Hill is unique in that it has relatively low nutrient concentrations
and is relatively clear. It also has a lot of timber in the transition and riverine zones, and it is possible that the geosmin was not coming from the water column but from benthic algae. However, we did some investigating and were unable to find any indication that benthic algae were responsible for the T&O events in Big Hill.
-Deb B. (KWO) asked what the land-use was before Big Hill was flooded. We should also consider prior land-use for all study reservoirs.
-Sam thought that it was cropland.
-Jason pointed out that Big Hill is relatively clear and as a result light penetrates deeper than in the other reservoirs. Therefore, while total algal biomass may be low, there is a greater volume of water in which algae can grow relative to more turbid reservoirs.
-Jerry pointed out that there are only a few taxa of cyanobacteria that dominate KS reservoirs and that these algae are morphologically distinct which would make it relatively easy to learn to distinguish the differences and make correct IDs. Therefore, water treat
ment personnel could use algal counts as an early warning indicator. The Cities of Tulsa and Springfield currently conduct regular algal counts on site.
-Jennifer G. pointed out the Actinomycetes cause T&O problems in TX reservoirs. However, not much is known about Acitnomycetes and their effects on T&O events. More research is needed.
-It was pointed out that geosmin concentrations tended to be higher in samples collected from the pump house than in samples collected from the reservoir surface near the tower. This likely resulted from differences in environmental conditions after the water is taken from the reservoir or because it is collected from different depths.
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