Correlations between Total Solids, Total Suspended Solids, Total Volatile Suspended Solids, and Phosphate at Deer Creek Reservoir

Abstract

Deer Creek Reservoir, located in Utah, supplies municipal and agricultural water for Utah and Salt Lake counties. During the past four decades the high levels of total phosphorus and dissolved oxygen in the water have introduced both taste and odor problems from algae growth, which have necessitated additional treatment to clean the water. In an attempt to discover why late summer algae blooms continue to persist at Deer Creek, the Brigham Young University Deer Creek Research Group collected data using several water quality laboratory tests on samples from 11 different sampling sites within the reservoir: total solids (TS), total suspended solids (TSS), total volatile suspended solids (TVSS), and phosphate. These tests were performed on samples collected during the summers of 2010 (May through October) and 2011 (April through November). Samples from Secchi depth were used for this analysis because of excessive variability introduced if samples from above and below the thermocline and at bottom layers of the reservoir were included. The purpose of this study is to determine if any correlations exists between these three measurements: solid, phosphate, and Secchi depths. We used total suspended solids as an indicator for algal mass. We suspect that phosphate is being trapped in solid material, specifically sediment, and being released into the reservoir slowly over time. Our analysis shows that solids at Deer Creek do not exhibit significant correlations with phosphate or Secchi depths. We suggest that a different approach to the phosphate problem be used that we should analyze and correlate Deer Creek phosphate with sediment oxygen demand (SOD) measurements taken using SOD chambers to correlate algae with potential phosphate release from sediments.