Excessive Fertilization/Eutrophication of
Lakes, Reservoirs, Estuaries and Near-Shore Marine Waters


A substantial portion of Drs. Lee and Jones-Lee’s professional work continues to be in the area of evaluation and management of the impacts of aquatic plant nutrients (nitrogen and phosphorus) on water quality/beneficial uses of waterbodies, including lakes, reservoirs, coastal marine waters, as well as riverine systems. Excessive fertilization (eutrophication) causes adverse impacts on recreational uses and aesthetics, raw water supply water quality (tastes & odors and THM formation), and fisheries resources through, among other things, oxygen depletion associated with algal decomposition. As discussed below, their work focuses on the causes, manifestation, and control of the wide range of excessive fertilization problems.

Dr. Lee’s work in eutrophication evaluation and management began in the 1960s when he established, developed, and directed the Water Chemistry Program in the Department of Civil and Environmental Engineering at the University of Wisconsin, Madison. During the 13 years under his direction, that program was highly involved in lake and reservoir water quality investigation and management; approximately 100 of his graduate students did their Masters theses or Ph.D. dissertations on various aspects of lake and reservoir water quality. One of the principal focal points of that work was excessive fertilization issues. Dr. Lee pioneered in the development of approaches for evaluating the impact of a various sources of nutrients, including activities and conditions in a waterbody's watershed, on waterbodies’ water quality.

In 1960, Dr. Lee was appointed vice-chair of the Lake Mendota Water Quality Management Committee. Lake Mendota is one of the most intensively studied waterbodies in the world due to the long history of limnological research conducted by the University of Wisconsin, Madison, faculty and students. From 1960 through the early 1970s many of the water chemistry studies conducted on Lake Mendota were under the direction of Dr. Lee. During that time Dr. Lee was also involved in Great Lakes water quality issues, and served as an advisor to the International Joint Commission for the Great Lakes and the US EPA on excessive fertilization issues. Over the years he has been an investigator or advisor on eutrophication-related water quality issues in many areas of the US as well as in the Netherlands, Norway, Italy, Spain, Israel, Jordan, Japan, the USSR, Dominican Republic, South Africa, Argentina, and Antarctica.

On behalf of the Water Resources Center at the University of Wisconsin, Madison, Dr. Lee developed the first comprehensive overview of the causes, processes, implications, and management of the eutrophication of waterbodies in the paper:

Lee, G.F., "Eutrophication," University of Wisconsin Eutrophication Information Program Occasional Paper no. 2, 32 pp (1970) [also published in Transactions of the Northeast Fish and Wildlife conference, pp 39-60 (1973), and available upon request from gfredlee33@gmail.com as EF014]

More recently, he and Dr. Jones-Lee were asked to contribute the following review of eutrophication:

Jones-Lee, A. and Lee, G. F., “Eutrophication (Excessive Fertilization),” In: Water Encyclopedia: Surface and Agricultural Water, Wiley, Hoboken, NJ, pp 107-214 (2005). [available at: http://www.gfredlee.com/Nutrients/WileyEutrophication.pdf]

Those reviews discuss the roles of nitrogen, phosphorus and other constituents in causing excessive fertilization-related water quality problems, as well as, and most importantly, approaches that can be used to manage excessive fertilization and evaluate the effectiveness of management strategies. Those two writings remain the most comprehensive reviews of eutrophication and its management.

Dr. Lee was also involved in the lake and reservoir management studies conducted by the state of Wisconsin in the late 1960s to early 1970s. As part of that program, whole-lake experimental approaches were used to assess the efficacy of a variety of strategies for evaluating and managing water quality in excessively fertile lakes; strategies evaluated included adding alum to the lake to remove phosphorus, aeration of the lake to mix the hypolimnion and epilimnion, hypolimnetic aeration, aquatic plant harvesting, among others. Dr. Lee was involved in a number of additional projects in the state of Wisconsin in which alum was used to treat whole lakes for phosphorus removal; he supervised the master thesis work of one of his students on this topic. Dr. Lee has developed specific guidance for discerning situations in which alum treatment for phosphorus removal can be effective, and where it should not be used. Critical to this assessment is the relative role of phosphorus in controlling excessive fertilization in the waterbody.

For a number of years beginning in the 1970s, Dr. Lee was a member of the American Water Works Association's national ‘Quality Control in Reservoirs’ Committee. During that time, the committee specifically addressed the value of mixing of lakes, either by aeration or pumping, for the purpose of managing eutrophication-related water quality problems. It was the committee's conclusion, supported by the fundamental chemistry of nutrients, that aeration of a whole waterbody could be significantly adverse to improving eutrophication-related water quality characteristics. Oxygenation of the hypolimnion, however, could be effective in maintaining cold-water fisheries and improving water supply water quality by reducing nutrient transport from the hypolimnion to the epilimnion. In 1965 Dr. Lee published a paper,

Lee, G.F. and Harlin, C.C., "Effect of Intake Location on Water Quality," Industrial Water Engineering 2:36-40 (1965). [available upon request to gfredlee33@gmail.com as publication DW003].

which specifically addressed the importance of evaluating domestic water supply water quality as a function of depth, and how, through selective withdrawal, water utilities can optimize their water quality in a thermally stratified waterbody.

While working with the state of Wisconsin Department of Conservation, Dr. Lee studied the impact of aeration of Comstock Reservoir on water quality. He examined the impact of aeration not only on chemical and biological characteristics of the reservoir, but also on the fisheries of the waterbody. Dr. Lee has had extensive experience in the evaluation of the impacts of various types of chemicals used to control algae and other aquatic weeds, including copper and diquat, on a waterbody's water quality and fisheries. Further, he is familiar with regulatory issues associated with the use of chemicals for aquatic plant control and their impact on non-target aquatic life. More recently, in support of the DeltaKeeper and the California State Water Resources Control Board, Dr. Lee developed guidance for evaluating the water quality impact of herbicides used to control excessive growths of aquatic weeds, on non-target organisms:

Lee, G. F., “Developing a Reliable Program to Monitor Water Quality Impacts of Aquatic Pesticides,” Report of G. Fred Lee & Associates, El Macero, CA (2004). [available at: http://www.gfredlee.com/Nutrients/Aq-Pest-MonPgm.pdf]

Dr. Lee has had extensive experience in assessing and managing the couplings among eutrophication, eutrophication control, and fish and other aquatic organisms. He and Dr. Jones-Lee published what has become recognized as one of the most comprehensive reviews of the impacts of eutrophication and water quality management on fish populations:

Lee, G.F. and Jones R.A., "Effects of Eutrophication of Fisheries," Reviews in Aquatic Sciences, 5:287-305, CRC Press, Boca Raton, FL (1991), [http://www.gfredlee.com/Nutrients/fisheu.html]

That paper reviews how managing algae-related water quality in a reservoir can influence the fisheries of the waterbody.

During the 1970s, Dr. Lee was awarded the US EPA contract to develop a synthesis report for the US part of the Organization for Economic Cooperation and Development (OECD) eutrophication studies. The approximately $50-million OECD eutrophication studies examined the nutrient load—eutrophication-related water quality response relationships in about 200 waterbodies located in 22 countries (in western Europe, North America, Japan, and Australia) over a five-year period. Dr. Lee served as an advisor to the overall international studies, as well as developed the US OECD report synthesizing the data on about 40 US waterbodies. Dr. Lee's primary contribution to this effort was in the development, evaluation, and application of empirical nutrient load—eutrophication-response relationships that can be used by water utilities and others to examine how land use in a waterbody's watershed influences nutrient transport to the waterbody from the watershed and then, the waterbody's water quality. Drs. Lee and Jones-Lee and their associates have published extensively on this topic including several comprehensive reviews such as,

Lee, G. F., Rast, W. and Jones, R. A., "Eutrophication of water bodies: Insights for an age-old problem," Environmental Science & Technology 12:900-908 (1978). http://www.gfredlee.com/Nutrients/Eutrophication-EST.pdf

Jones, R. A. and Lee, G. F., "Eutrophication Modeling for Water Quality Management: An Update of the Vollenweider-OECD Model," World Health Organization's Water Quality Bulletin 11(2):67-74, 118 (1986). http://www.gfredlee.com/Nutrients/voll_oecd.html.

Jones, R. A. and Lee, G. F., "Chlorophyll-A Raw Water Quality Parameter," Journal American Water Works Association 74:490-494 (1982). [available upon request from gfredlee33@gmail.com].

Key to the development and evaluation of effective nutrient/eutrophication control strategies is the ability to reliably assess the improvement in water quality that can result, or has resulted, from various control strategies. One of the important results of their work with the Vollenweider-OECD eutrophication modeling approach was their demonstration of the predictive capability and reliability of the models using data collected before and after nutrient load alterations. That work was discussed in:

Rast, W., Jones, R. A. and Lee, G. F., “Predictive Capability of US OECD Phosphorus Loading-Eutrophication Response Models,” Journ. Water Pollut. Control Fed. 55:990-1003 (1983). [http://www.gfredlee.com/Nutrients/PredictiveCapabilityOECD.pdf]

While serving as chairman of the AWWA national Quality Control in Reservoirs Committee, Drs. Lee and Jones-Lee developed several committee reports that were designed to assist water utilities in managing their raw water quality:

Lee, G. F. and Jones, R. A., "Study Program for Development of Information For Use of Vollenweider-OECD Eutrophication Modeling in Water Quality Management for Lakes and Reservoirs," G. Fred Lee & Associates, El Macero, CA (1992). [available as EF007 upon request from gfredlee33@gmail.com].

Lee, G.F. and R.A. Jones, "Determination of Nutrient Limiting Maximum Algal Biomass in Waterbodies," G. Fred Lee & Associates, El Macero, CA (1998). [http://www.gfredlee.com/Nutrients/nut_limit.html]

Dr. Lee was asked by the organizers of a University of California Water Resources Center conference devoted to water supply source water quality issues, to develop a review of water quality issues in the Sacramento/San Joaquin Delta in the Central Valley of CA. This resulted in Drs. Lee and Jones-Lee’s publication of a paper and report:

Lee, G. F. and Jones, R. A., “Managing Delta Algal-Related Drinking Water Quality: Tastes and Odors and THM Precursors,” Published in “Protecting Drinking Water Quality at the Source,” proceedings of a Conference, Univ. of California Water Resources Center, Report no. 76, October (1991).

Lee, G. F. and Jones, R. A., “Regulating Drinking Water Quality at the Source,” Presented at Univ. of California Water Resources Center Conference, “Protecting Drinking Water Quality at the Source,” Sacramento, CA, April 3-4 (1991). http://www.gfredlee.com/WSWQ/wswqsour.htm

Those publications specifically discuss issues of how land use within and upstream of the Delta influences the quality of the domestic water supply derived from the Delta. Further, as part of the CA/NV AWWA Section Source Water Quality Committee, Dr. Lee developed a review for the committee on the impact of the drought in the late 1980s - early 1990s on domestic water supply water quality:

Lee, G. F. and Jones, R. A., "Impact of the Current California Drought on Source Water Supply Water Quality," Presented at CA/NV AWWA Fall conference, Anaheim, CA, 30pp, October (1991). [available upon request from gfredlee33@gmail.com].

That paper reviewed how the algae-related quality of the water derived from the Delta adversely impacts domestic water supply water quality through taste and odors and THMs.

Much of Dr. Lee's work on excessive fertilization of waterbodies has focused on eutrophic/hypertrophic waterbodies in which blue-green algae dominate the flora. Blue-green algae can be a significant source of tastes and odors in domestic water supplies. A number of Dr. Lee’s graduate students did their Ph.D. dissertations on water quality issues associated with blue-green algae; topics investigated included nitrogen fixation by blue-green algae, the role of thermocline migration and erosion in the transference of hypolimnetic nutrients to surface waters where they stimulate blue-green algal blooms, and the role of sediments and other sources of nitrogen and phosphorus compounds in controlling blue-green algae dominance in waterbodies.

Dr. Lee has been involved in several major projects on behalf of water utilities specifically designed to examine how land use in a water supply reservoir’s watershed influences raw water quality. In what is believed to be one of the most comprehensive studies of this type ever undertaken, Dr. Lee conducted a multi-year, several hundred-thousand-dollar project on behalf of the city of Dallas, Texas, water utility. That study specifically addressed the issues of how changes in land use in the watershed of Lake Ray Hubbard, one of the primary water supply reservoirs for the city of Dallas, influenced taste- and odor-related water quality. The study considered not only algae but also actinomycetes as sources of taste and odors. Dr. Lee and one of his graduate students published a paper on the results of that investigation:

Archibald, E. M. and Lee, G. F., "Application of the OECD Eutrophication Modeling Approach to Lake Ray Hubbard, Texas," Journal American Water Works Association, 73:590-599 (1981). http://www.gfredlee.com/Nutrients/OECDLakeRayHub.pdf

Dr. Lee conducted a similar study for the Olathe, Kansas, water utility, in which he examined the relationship between land-use practices in Lake Olathe's watershed and the waterbody's raw water quality.

Dr. Lee also conducted a study on behalf of the Lubbock, Texas, water utility related to controlling THMs in its finished water by controlling the sources of organic carbon in its raw water derived from Lake Meredith. That was an unusual situation in that a freshwater sponge was growing in the raw water transmission line between the reservoir and the water utility; it developed to a thickness of a foot or more inside the pipe. The sponge was obtaining its nutrients from organics derived from in-line open reservoirs along the transmission line.

One of the areas that Dr. Lee has pioneered is the development of guidance to water utilities and others on how to design a water supply reservoir to minimize raw water quality problems. He presented a paper on this topic:

Lee, G. F. and Jones, R. A., "Predicting Domestic Water Supply Raw Water Quality in Proposed Impoundments," IN: Proc. American Water Works Association 1984 Annual Conference Proceedings, pp 1611-1630 (1984). http://www.gfredlee.com/WSWQ/RawWQProposedImp84.pdf

Drs. Lee and Jones-Lee assisted the Municipal Water Supply Authority for Santo Domingo in the Dominican Republic to evaluate the adequacy of a proposed water treatment plant for treating the waters derived from a yet-to-be-developed water supply reservoir on a river. They were able to develop predictions of the raw water quality in the proposed reservoir based on land use in the reservoir’s watershed. From that prediction, they concluded that the proposed water treatment plant would not be able to produce high-quality water, and recommended changes in the design of the treatment plant to more appropriately address the water quality characteristics that would be expected based on the proposed reservoir’s watershed.

Dr. Lee has been active for many years in work on the impacts of releases from reservoirs on downstream water quality. For example he served as an advisor to the Tennessee Valley Authority and other agencies on the impact of reservoir releases on downstream water quality and co-authored a review on this topic:

Krenkel, P. A., Lee, G. F. and Jones, R. A., "Effects of TVA Impoundments on Downstream Water Quality and Biota," IN: The Ecology of Regulated Streams, Plenum Press, New York, pp 289-306 (1979). [available upon request from gfredlee33@gmail.com.]

Another major concern about the impact of excessive fertilization on water quality is the utilization of dissolved oxygen in the bacterial decomposition of algae, which can lead to low dissolved oxygen or anoxic conditions in waterbodies. Drs. Lee and Jones-Lee served as the coordinating principal investigators for a $2-million CALFED project devoted to evaluating the cause and developing control programs, for the low dissolved oxygen problem in the San Joaquin River (SJR) Deep Water Ship Channel (DWSC) near the Port of Stockton. One of the primary causes of the dissolved oxygen depletion there is the oxygen utilization in the decomposition of algae that had developed upstream in the SJR. Upon entering the DWSC the algae settle, die and decompose; the decomposition depletes the oxygen resources of the channel. They developed a comprehensive synthesis report and supplementary discussion on that situation:

Lee, G. F. and Jones-Lee, A., “Synthesis and Discussion of Findings on the Causes and Factors Influencing Low DO in the San Joaquin River Deep Water Ship Channel Near Stockton, CA: Including 2002 Data,” Report Submitted to SJR DO TMDL Steering Committee and CALFED Bay-Delta Program, G. Fred Lee & Associates, El Macero, CA, March (2003). http://www.gfredlee.com/SJR-Delta/SynthesisRpt3-21-03.pdf

Lee, G. F. and Jones-Lee, A., “Supplement to Synthesis Report on the Low-DO Problem in the SJR DWSC,” Report of G. Fred Lee & Associates, El Macero, CA, June (2004). http://www.gfredlee.com/SJR-Delta/SynthRptSupp.pdf

They have become involved in the issues of the development of appropriate approaches for controlling phosphorus from agricultural land runoff to improve those conditions, focusing in part on the comparative effects of controlling total phosphorus versus algal-available P in runoff waters. Dr. Lee's reviews,

Lee, G. F., “A Proposal for Assessing Algal-Available Phosphorus Loads in Runoff from Irrigated Agriculture in the Central Valley of California,” Report of G. Fred Lee & Associates, El Macero, CA, November (2006). http://www.gfredlee.com/Nutrients/AlgalAssayAvailP.pdf Lee, G. F., "Assessing Algal Available Phosphorus," Proceedings of US EPA Science Symposium: Sources, Transport, and Fate of Nutrients in the Mississippi River and Atchafalaya River Basins, Minneapolis, MN, November 7-9 (2006). http://www.gfredlee.com/Nutrients/AvailPEPASymp06.pdf

address those issues.

Drs. Lee and Jones-Lee are serving as advisors on the excessive fertilization of the Upper Mississippi River, examining the relative roles of agricultural land runoff and domestic wastewater sources in contributing to the problems. They are also working with the California Central Valley Regional Water Quality Control Board on the development of guidance for evaluating the water quality impact nitrogen and phosphorus in agricultural runoff/discharge and presented their findings in,

Lee, G. F. and Jones-Lee, A., “Assessing the Water Quality Significance of N & P Compound Concentrations in Agricultural Runoff,” Invited presentation to the Agrochemical Division, American Chemical Society national meeting, San Francisco, CA, September (2006). http://www.gfredlee.com/Nutrients/N-PRunoffACS.pdf

Lee, G. F., and Jones-Lee, A., “Assessing Water Quality Significance of N & P Compound Concentrations in Agricultural Runoff,” PowerPoint Slides for Invited Paper Presented at Agrochemical Division, American Chemical Society National Meeting, San Francisco, CA, September (2006). http://www.gfredlee.com/Nutrients/N-PSlidesACS.pdf

With support of the California State Resources Board they developed,

Lee, G. F., and Jones-Lee, A., “Managing Nutrient (N & P) Water Quality Impacts in the Central Valley, CA,” [Excerpts from: Lee, G. F. and Jones-Lee, A., “Review of Management Practices for Controlling the Water Quality Impacts of Potential Pollutants in Irrigated Agriculture Stormwater Runoff and Tailwater Discharges,” California Water Institute Report TP 02-05 to California Water Resources Control Board/Central Valley Regional Water Quality Control Board, 128 pp, California State University Fresno, Fresno, CA, December (2002)], Report of G. Fred Lee & Associates, El Macero, CA (2002). http://www.gfredlee.com/SJR-Delta/CentralValleyNutrientMgt.pdf

That report presents a comprehensive review of nutrient evaluation/management issues. More recently, Drs. Lee and Jones-Lee worked with the California Water Environmental Modeling Forum to develop and present a workshop devoted to Delta Nutrient Water Quality Issues. Information on that workshop is available in

Lee, G. F., and Jones-Lee, A., “Delta Nutrient Water Quality Modeling Workshop — Background Information,” Report of G. Fred Lee & Associates, El Macero, CA, September (2007). [available at: http://www.gfredlee.com/Nutrients/NutrWorkshopRev4.pdf]

A list of their publications concerning eutrophication evaluation and management is available on this website. For further information, contact G. Fred Lee at gfredlee33@gmail.com

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