1. Watershed characterization and source water identification

Goal 1: Understand what form disinfection byproduct (DBP) precursors take in the environment, how they are transported, when, and why.
Goal 2: Develop relationships that will make it easier to identify source waters likely to be problematic with respect to DBPs.

Summary: A study was conducted to determine if one could identify the infiltration area of groundwater based on the dissolved organic matter (DOM) signature. Initial results suggested that the DOM signature could be used to identify general areas of water infiltration. This is important so we can protect source water quality. If we know how infiltration areas impact DOM, we can predict how likely we are to get DBP precursors in water plants and how this might change with the seasons.

A series of studies were conducted to help understand how DOM is different when it comes from watersheds with different vegetation types. It was found that the vegetation cover has a quantifiable impact on the type of DOM in leachates (e.g., groundwater). Based on relationships previously developed relating the DOM characteristics to DBPs, one could get a general idea about the potential risk for DBP precursor material as a function of the cover vegetation in a watershed.

A series of studies were conducted to evaluate the impact of source water on DBP formation. These studies found that there are fundamental differences between the DOM in Alaska water sources and those in the lower 48 states. It was found that DBPs could be predicted very well by the simple test for ultraviolet absorbance at 254 nanometers (UV-254). This simple test could help identify water sources that will cause high DBP concentrations in finished water.

Publication products:
Seelen, S., D. White, K. Yoshikawa, and V. Autier. “Influence of vegetation on DOM”, Journal of Environmental Engineering and Science. Pending publication.

White, D.M., D.S. Garland, D.S., J. Narr., C. Woolard. (2003), Natural organic matter and DBP formation potential in Alaskan water supplies, Water Research, Vol 37/4 pp 939 - 947.

White, D., K. Yoshikawa, and D.S. Garland, 2002), Use of dissolved organic matter to support hydrologic investigations in a permafrost dominated watershed, Journal of Cold Regions Science and Technology, Vol. 35, pp. 27-33.

Seelen, C., White, D.M., K. Yoshikawa, V. Autier, (2004), How chemical differences in soil leachates relate to groundcover, Proceedings of the 2004 Cold Regions Engineering and Construction Conference.

White, D.M., D.S. Garland, C. Woolard, and J. Narr (2002) Investigations into disinfection by-product formation and control for small drinking water systems in Northern Regions, In. ed. Kelly Merrill, Cold Regions Engineering: Cold Regions Impacts on Transportation and Infrastructure, ASCE, Washington DC., pp. 991-999.

Narr, J., (2001), Disinfection by-product experiences in Alaskan village drinking water systems and the Caribou Poker Creeks Watershed, MS Thesis, UAF.

Seelen, S., (2004), How chemical differences in dissolved organic matter relate to vegetation, MS Thesis, UAF.

2. Water use practice

Goal: Understand the role of water use practices in rural communities that can lead to excess chlorination.

Summary: This study demonstrated the very high variation in flow demand in some Alaska water supplies. These flow variations make it very difficult to meet chlorination targets. High flow variations can result in over or under-chlorination of finished water.

Products:
Mandt, A., Analysis of flow variation in Alaska Water Supplies. MS Project report, UAF.

3. Water treatment practices

Goal: Compare water treatment techniques and their impacts on treated water quality.

Summary: Five different water filtration technologies were compared with respect to their ability to remove DBP precursors. Results found that the membrane filtration (micro/nano) was very effective, conventional filtration was moderately effective, but direct and cartridge filtration were ineffective at removing DBP precursors from water.

Products:
Myerchin, G., D. White, and C. Woolard, (in review), "Disinfection by-product formation during long term water storage in Alaska," ASCE Journal of Cold Regions Engineering.

McGee, G., (2002), Determining the impacts of storage practice and treatment technology on the formation of disinfection by-products, MS Thesis, UAF.

4. Water storage practices

Goal: Characterize the impact of water storage duration on DBP formation.

Summary: Long term storage has a significant impact on DBP formation in water. Much of the increase in DBPs, however, was observed in the first 3 months of storage, and probably in the first month. Storing filtered, but unchlorinated water could significantly reduce the accumulation of DBPs in finished water. This strategy would require that the water be chlorinated on demand. Short term storage would still be required once the water is chlorinated to provide contact time.

Products:
Myerchin, G., D. White, and C. Woolard, (in review), “Disinfection by-product formation during long term water storage in Alaska”, ASCE Journal of Cold Regions Engineering.

McGee, G., (2002), Determining the impacts of storage practice and treatment technology on the formation of disinfection by-products, MS Thesis, UAF.

5. Contaminants in rainwater catchments

Goal: Characterize and quantify contaminants found in rainwater catchments across Alaska.

Summary: The construction material has a significant impact on water quality in rainwater catchments. In particular, the water quality in catchments that have contact with lead and copper can cause the rainwater to accumulate these metals in excess of EPA regulated limits.

Products:
Hart, C., and D. White, (in press), “Influence of materials on rainwater catchments”, Journal of Environmental Engineering and Science.

Hart, C., (2003), Water Quality from Rainwater Catchments Throughout Alaska, MS Thesis, UAF.

Myerchin, G., (2008), B. Schnabel, A. Tidwell, and D. White, Optimal Storage Volumes for Rainwater Catchment Systems in Alaska

6. Monitoring and operation of advanced treatment technology

Goal: Operate and monitor a membrane filtration plant in a remote camp for the purposes of developing operational protocols appropriate for small rural communities.

Summary: A membrane (micro/nano) filtration system was constructed and installed at a remote work camp in the Brooks Mountain Range in Alaska. The water treatment system is being outfitted with internet communication so that the control system can be operated remotely. The system has been installed and the remote operation component of the project is underway.

Products: None yet

UAF Applied Research Contact:
Dan White, PE, PhD