Waterworks Archive

Microcystin, tufa and solute transport are involved in KWRI research projects this year

Based on recommendations from the Kentucky Water Research Institute’s Research and Policy advisory committee, three new research projects have been funded this year in the KWRI’s Annual Institutes Allotment Program. The projects are co-funded by the U.S. Geological Survey, which provides one-third of the funds. The University of Kentucky provides the balance of the funding.

The names of the principal investigators and their affiliations are listed below along with the titles and descriptions of the new research projects.

"A Full-Scale Plant Evaluation of the Removal of Microcystine, a hepatotoxin, from Drinking Water"

Roger Blanchard, Dept. of Chemistry, Miriam S. Kannan and Judy A. Westrick, Dept. of Biological Sciences, Northern Kentucky University

The Ohio River is the largest, single, surface water source of Kentucky drinking water. More than one third of Kentuckians drink treated Ohio River water, according to the Kentucky Environmental Protection Agency (KEPA). However, the Ohio River has become home to Microcystis, a cyanobacteria (blue-green algae). Microcystis contains microcystin, an intracellular hepatotoxin, which, even at low doses, has been linked to gastrointestinal tract and liver cancer.

The primary objective of this study is to determine how much microcystin is removed from drinking water by full-scale treatment consisting of conventional and advanced technologies. An additional objective is to assess the presence or absence of microsytin in Ohio River water. This study will be one of the initial screens for the KEPA and the U.S. Environmental Protection Agency. Identifying and enumerating cyanobacteria and measuring toxin concentrations will provide drinking-water suppliers with a simple tool, a cell/toxin ratio, that can be used for estimating the risk potential.

The Newport (Ky.) Drinking Water Treatment Plant is the site of the study. The plant will be replacing its conventional treatment technology with Actiflo ballasted flocculation, which was reported to have removed 99 percent of all algae in a Pennsylvania pilot study. This full-year KWRI study will allow the KEPA to evaluate the efficiency of Actiflo ballasted flocculation on regional waters from comprehensive algae, pH, turbidity, hardness, and DOC data.

The study will determine the algae speciation throughout the year, and before and after each process. This will allow for the evaluation of the effects of seasonal source-water quality and treatment unit processes on the removal of individual alga species.

This study is a collaboration between academia and the drinking-water industry that should have benefits to both parties. The Newport plant will get in-house research that it could not otherwise afford, and the faculty and their students will get exposure to applied environmental research.

With data from this study, the Newport plant and similar, smaller facilities will be able to optimize their treatment process to minimize the amount of microcystin in the finished water. They will also be able to use protocols and analyses from this study to efficiently evaluate future treatments, which will result in better finished water quality.

"Records of Holocene Climatic and Hydrologic Variability in Spring Tufa from Kentucky: Will Global Climate Changes Affect Water Availability in Karst Terrains of the Mid-Continent Area?"

Slawek M. Tulaczyk, Department of Geological Sciences, University of Kentucky.

This project will investigate the idea that future global warming may be associated with increased occurrence of droughts. Given the short residence time of groundwater in karst aquifers, which lay under more than 50 percent of Kentucky and 20 percent of the U.S., karst terrains may be especially vulnerable to drought-induced water shortages.

By looking into the past, Tulaczyk hopes to find answers about the future. He will look for geochemical evidence of past droughts in spring tufa, a secondary calcite deposit, to help make predictions about possible future effects of global warming.

Previous studies have shown that isotopic and chemical composition of secondary calcite deposits are sensitive to variations in the climatic and environmental conditions occurring when the calcite is precipitated. Different chemical elements leach into groundwater filtering through overlaying soils into karst aquifers become trapped in the layers of precipitated calcite. Some of the tufa Tulaczyk will be investigating was deposited during the warmer part of the Holocene, which may be analogous to climatic conditions during future global warming.

Tulaczyk will be looking at spring tufa from the Three Hundred Springs, located on the banks of Green River in the mature karst terrain of the Penny Royal Plain near Cave City, Ky.. He will be searching for the geochemical proxies of past drought conditions during both the colder and warmer parts of the Holocene (ca. 0-5,000 years B.P. and 5,000 to 8,000 years B.P., respectively).

A simple geochemical model will be constructed to make quantitative predictions of the potential influence and groundwater recharge in this part of Kentucky. This model and the data obtained in this study may ultimately be used as to help make decisions regarding future management of water resources in the karst terrains of Kentucky and neighboring states.

"Measurement and Prediction of Solute Transport Parameters for Kentucky Soils"

Edmund Perfect, Department of Agronomy, University of Kentucky

Widespread use of agricultural chemicals and increasing applications of animal wastes to soils pose a threat to groundwater quality. Agricultural chemicals that are not adsorbed, volatized, lost in runoff or taken up by plants must pass through the variably saturated (vadose) zone to reach groundwater. Predicting transport processes within the vadose zone underlaying agricultural fields is essential to investigating agriculture’s role in nonpoint source pollution

This project will investigate the influence of soil properties on the transport process contributing to the contamination of groundwaters under saturated conditions. Even though Kentucky soils are normally only saturated for relatively short periods of time, solute dispersivity under saturated conditions is a very important parameter, because a large portion of the total annual movement of water and solutes through the vadose zone can occur during these events. While the focus of this project will be on non-reactive solutes, such as chloride and nitrate, the estimated dispersivities could also be used to predict the transport of reactive chemicals, such as pesticides.

Perfect will estimate input parameters for the modified convection-dispersion equation (CDE) by performing miscible displacement experiments on undisturbed core samples from a wide variety of Kentucky soils. Solute transport in the vadose zone can be predicted using the CDE, modified for structured conditions by inclusion of mobile and immobile water domains. Perfect will also develop pedotransfer functions to predict these parameters from the water retention curve and other more easily measured soil properties. Model prediction could be used to develop best management practices (BMPs) for agricultural chemicals and animal wastes applied onto structured soils. If implemented, the resulting BMPs should result in reductions in no-point sources of pollution and improvements in groundwater quality.

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Last modified: November 1999

Copyright ©1999 Kentucky Water Research Institute,
University of Kentucky