See the Latest Water Quality Monitoring Data from the FoRR Monitoring Team!

FoRR took to the river on July 17 to monitor three of our five sites in the Reedy River watershed. Our sites include the following:

Site #1: Reedy River just downstream of Swamp Rabbit Cafe

Site #2: A small tributary of the Reedy River in Falls Park 

Sit #3: Reedy River on Mauldin Road upstream of ReWa's headquarters

Site #4: Reedy River on Greenville Tech's Brashier campus in Simpsonville

Site #5: Reedy River in Cedar Falls Park in Simpsonville

Sites 1, 2, and 3 were monitored this month. Sites 4 and 5 were not monitored due to poor weather conditions during the normal week of sampling. The SC Adopt-a-Stream program dictates that volunteers should not monitor within 24 hours of a significant precipitation event. We hope to have sites 4 and 5 monitored again next month!

The pH results for July were consistent with our findings in July, with sites showing only very small changes, if any changes were present at all from last month’s results. 

The air and water temperatures for July’s sampling event increased again, as expected through the summer months. The air temperatures across the three Greenville sites increased by a range of 1.5°C to 3°C, with an average air temperature increase of 2.3°C and temperatures ranging from 23.5°C to 26.5°C. The water temperature across all three sites increased either 4 or 5°C at each site, with an overall average water temperature of ~23°C.

July's dissolved oxygen (DO) results changed very little compared to June's results with a maximum decrease of only 0.4 mg/L at both Falls Park and Mauldin Road. The site near Swamp Rabbit Cafe only decreased by 0.1 mg/L this month. The slight decreases at all sites can be attributed to the water temperatures that increased once again this month which is typical for this time of year since water temperature and dissolved oxygen levels have an inverse relationship. The average DO level this month was 6.2 mg/L, which is just slightly higher than the average DO in July 2022 (higher DO is typically a good thing, so this might reflect some positive change in the watershed). We do not expect to see DO levels rise again until temperatures begin to decrease in the fall.

The E. coli bacteria results were low this month, with the highest count of only 267 CFU/100mL coming in at our downstream-most Greenville site on Mauldin Road. The other two sites, Falls Park and Swamp Rabbit Cafe, registered just slightly lower at 200 CFU/100mL. These results are all well below the state-defined “high threshold” of 349 cfu/100mL, and much lower than the "problematic threshold" of 1,000 CFU/100mL. The low E. coli results are likely a result of the low-precipitation conditions in the days prior to sampling since rainfall events in urban areas result in stormwater runoff. Stormwater runoff carries pollutants, including animal waste and sediment, to the river and introduces a high volume of water to stream systems. The high flows typically also stir up the stream bed sediment, which sequesters bacteria, and reintroduces this into the stream water. This can lead to higher E. coli levels after heavy rainfall events, and can also explain why we had low E. coli levels after very little rain prior to this sampling event.

This month's turbidity readings were very similar or the same as last month's levels, with only one site showing a slight increase from 6 to 7 NTUs at Swamp Rabbit Cafe. The other two sites, Falls Park and Mauldin Road, showed no change and once again had levels of 5 NTUs. The low precipitation levels in the days prior to sampling, coupled with the slightly lower than usual water levels, are once again correlating factors with the low turbidity levels (meaning that the water was relatively clear, with low turbidity or cloudiness).

July's results and the SC state standards are included for comparison below. All results were within SC state standards. 

July 2023 Monitoring Results: