Trials are currently taking place on Utah Lake (surface area 38,445 hectares), one of the largest natural freshwater lakes in the western United States, to address the recurring problem of blue-green algae. SePRO Corporation and Aqua Technex under the direction of the Utah Lake Commission and partners, are working together to demonstrate technologies (including Phoslock) that could help the lake’s recovery.

Utah Lake    ...as viewed from 40 miles high!  (source:  Google Earth)





Lincoln Marina

A lake ‘curtain’ is being used to contain and control the testing site of Lincoln marina whilst Phoslock is applied and monitoring takes place for algae ID & biomass, nutrients and general water parameters (Alkalinity, Conductivity, DO, Hardness, pH, Turbidity). Samples are being taken from two specific locations within the site on days 0, 1, 2, 7, 14 and 21.  This will be followed up with a full report and data analysis.  Click here to read the official press release from the Utah Lake Commission.



The bigger picture...



Map showing Jordan River Basin  (source: Wikimedia)

Nearly 60% of the inflow to Utah Lake comes from two major tributaries – the Provo River and the Spanish Fork. The lake’s only river outlet is the Jordan at the northern end through a closely regulated pumping station.  Evaporation accounts for 42% of the outflow which leaves the lake slightly saline.



As in many cases of lake eutrophication, a multitude of factors have combined over the years to varying degrees in Utah Lake to encourage the proliferation of blue-green algae.  Specifically, agricultural run-off (particularly from land to the south) and high turbidity of the lake water caused by a combination of being relatively shallow and having an excessive amount of bottom-feeding fish (e.g. common carp).  Common carp were introduced in the late nineteenth century and create a challenge for the lake’s authorities.  These causes coupled with rapid urban development over the last 100 years have of course hugely affected the ecological balance of the lake, with raw sewage entering the lake up to as late as 1967.  Improvements have been made since then but combined with groundwater run-off from almost 4,000 square miles, it is inevitable an excess of nutrients will have accumulated over many years into lake sediments.  Whilst untreated, releasable phosphorous bound in sediments will continue to rise into the overlying water column and the symptoms of nutrient enrichment will likely continue.



No surprise then that Dr. Willis H. Brimhall’s (of Brigham Young University) study, carried out in the 1970’s    …”found that Utah Lake was less turbid in pioneer times. Brimhall’s study noted that since its inception, the lake has never been perfectly clear because it has always been shallow. This lack of depth contributes to its turbidity, large loss of water to evaporation, slightly saline water, warm summer temperatures, and abundance of algae. Brimhall also concluded that some 28 feet of sediment accumulated on the lake’s bottom over the past 10,000 years….”  - This extract from part of a fascinating publication – “Utah Lake: Legacy” (http://utahlakecommission.org/wp-content/uploads/2011/09/Utah_Lake_Legacy.pdf) written by D Robert Carter and produced by the June Sucker Recovery Implementation Program is well worth looking at for the rich history it provides on Utah Lake.



Carter’s section – “Characteristics of a shallow lake” on page 77 (of the 87 page pdf document) also provides a brilliantly clear written description of the significance that aquatic plants (macrophytes) play in creating stability in such a lake along with the devastating effects that can happen when non-native fish species are introduced in conjunction with the onward march of urbanisation surrounding a lake.



However, as the Utah Lake Commission emphasises, one should not let the algal blooms of this lake get out of perspective. This is a vast, if relatively shallow lake with a large variety of mini eco systems with in it.  For example whilst one part of the lake might be suffering from an algal bloom, another part of the lake might have water clean enough to drink.



Today’s issues are nevertheless being taken extremely seriously by the Utah Lake Commission and as part of their ongoing program the Utah Lake Water Quality Study (ULWQS) https://deq.utah.gov/water-quality/utah-lake-water-quality-study was set up. 

Subsequently it is hoped the trials which are currently underway will eventually lead to a decisive plan of action to assist with the reversal of the lake’s increasing eutrophication. Intervention will help move Utah Lake towards a healthier ecosystem for everyone to enjoy for generations to come.