Water Quality Events

2026

6/14/2026 TOC levels below 1.0 ppm. This notice is for industrial purposes only.
6/14/2026 TOC levels above 1.0 ppm. This notice is for industrial purposes only.
6/9/2026 TOC levels below 1.0 ppm. This notice is for industrial purposes only.
6/9/2026 TOC levels above 1.0 ppm. This notice is for industrial purposes only.
4/4/2026 TOC levels below 1.0 ppm. This notice is for industrial purposes only.
4/3/2026 End of partial dewatering of Wapato Lake The US Fish and Wildlife Service began partially dewatering Wapato Lake in accordance with their restoration goals. Pumping lasted 32 days. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
3/27/2026 TOC levels above 1.0 ppm. This notice is for industrial purposes only.
3/18/2026 Treatment Change: Caustic Soda no longer being added to Rapid Mix due to improvements in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
3/12/2026 Treatment Change: Caustic Soda added to Rapid Mix, due to changes in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
3/3/2026 Start of partial dewatering of Wapato Lake The US Fish and Wildlife Service began partially dewatering Wapato Lake in accordance with their restoration goals. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
2/23/2026 TOC levels below 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
2/23/2026 TOC levels above 1.0 ppm following recent weather event. This notice is for industrial purposes only.

Past Events

2025

12/29/2025 Treatment Change: Caustic Soda no longer being added to Rapid Mix due to improvements in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
12/20/2025 TOC levels below 1.0 ppm following recent weather event. This notice is for industrial purposes only.
12/19/2025 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
12/11/2025 TOC levels below 1.0 ppm following recent weather event. This notice is for industrial purposes only.
12/10/2025 Treatment Change: Decreased doseage of caustic soda below 40 mg/L The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
12/9/2025 Treatment Change: Increased doseage of caustic soda above 40 mg/L The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
12/7/2025 Treatment Change: Caustic Soda added to Rapid Mix, due to changes in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
11/29/2025 TOC levels below 1.0 ppm following recent weather event. This notice is for industrial purposes only.
11/28/2025 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
11/19/2025 TOC levels below 1.0 ppm following recent weather event. This notice is for industrial purposes only.
11/14/2025 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
11/2/2025 Treatment Change: Caustic Soda added to Rapid Mix, due to changes in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
10/21/2025 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
9/29/2025 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
5/20/2025 TOC levels below 1.0 ppm following recent weather event. This notice is for industrial purposes only.
5/9/2025 End of partial Wapato Lake dewatering The US Fish and Wildlife Service began partially dewatering Wapato Lake in accordance with their restoration goals. Pumping lasted approximately 39 days. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
3/31/2025 Start of partial Wapato Lake dewatering The US Fish and Wildlife Service began partially dewatering Wapato Lake in accordance with their restoration goals. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
3/22/2025 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
3/1/2025 Treatment Change: Caustic Soda no longer being added to Rapid Mix due to improvements in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
2/27/2025 TOC levels below 1.0 ppm following recent weather event. This notice is for industrial purposes only.
2/26/2025 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
2/23/2025 Treatment Change: Caustic Soda added to Rapid Mix, due to changes in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.

2024

12/30/2024 Treatment Change: Caustic Soda no longer being added to Rapid Mix due to improvements in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
12/26/2024 Treatment Change: Caustic Soda added to Rapid Mix, due to changes in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
12/25/2024 Treatment Change: Caustic Soda no longer being added to Rapid Mix due to improvements in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
12/18/2024 Treatment Change: Caustic Soda added to Rapid Mix, due to changes in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
12/18/2024 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
11/30/2024 TOC levels below 1.0 ppm following recent weather event. This notice is for industrial purposes only.
11/25/2024 Treatment Change: Caustic Soda no longer being added to Rapid Mix due to improvements in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
11/20/2024 Treatment Change: Caustic Soda added to Rapid Mix, due to changes in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
11/6/2024 TOC levels above 1.0 ppm due to recent weather event. TOC analyzer has been fixed. This notice is for industrial purposes only.
10/31/2024 TOC levels above 1.0 ppm due to recent weather event. TOC analyzer undergoing maintenance issues and may not be reading accurately. This notice is for industrial purposes only.
4/17/2024 End of partial Wapato Lake dewatering Although pumping of Wapato Lake is an annual occurrence, this year the US Fish and Wildlife Service will not be fully dewatering the lakebed to meet their restoration goals. Pumping lasted 18 days. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
3/30/2024 Start of partial Wapato Lake dewatering Although pumping of Wapato Lake is an annual occurrence, this year the US Fish and Wildlife Service will not be fully dewatering the lakebed to meet their restoration goals. Pumping is expected to last approximately 30 days. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
2/6/2024 TOC levels below 1.0 ppm. This notice is for industrial purposes only.
1/8/2024 Treatment Change: Caustic Soda added to Rapid Mix, due to changes in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
1/6/2024 Treatment Change: Increase to the filter aid polymer. This notice is for industrial purposes only.

2023

12/13/2023 Treatment Change: Caustic Soda no longer being added to Rapid Mix due to improvements in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
12/6/2023 Treatment Change: Caustic Soda added to Rapid Mix, due to changes in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
11/6/2023 Treatment Change:  Caustic Soda added to Rapid Mix, due to changes in raw water chemistry. Treatment Change: Poor influent water quality (due to heavy rains) required an increase in the dosage of Chlorine. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
11/3/2023 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
10/27/2023 TOC levels below 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
10/25/2023 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
10/17/2023 TOC levels below 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
10/17/2023 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
10/14/2023 TOC levels below 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
10/12/2023 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
9/1/2023 TOC levels below 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
9/1/2023 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
5/18/2023 End of Wapato Lake dewatering This is an annual occurrence that continues until the lake is fully drained. Pumping lasted 51 days. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
3/21/2023 Start of Wapato Lake dewatering This is an annual occurrence that continues until the lake is fully drained, approximately 3-5 weeks. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
3/11/2023 Treatment Change: Caustic Soda no longer being added to Rapid Mix due to improvements in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
3/10/2023 Treatment Change: JWC dosage of filter aid polymer below the trigger notification level of 0.2 ppm due to improvements in raw water quality Treatment Change: Caustic Soda added to Rapid Mix due to changes in raw water chemistry. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.

2022

12/31/2022 TOC levels below 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
12/27/2022 TOC levels above 1.0 ppm due to recent weather events. Treatment Changes: Increases in raw water turbidity and organic matter incoming to the plant required an increase in the dosage of Aluminum Sulfate (Alum). This notice is for industrial purposes only.
12/26/2022 Treatment Change:  Caustic Soda added to Rapid Mix, due to changes in raw water chemistry The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
12/12/2022 TOC levels below 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
12/10/2022 TOC levels above 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
12/5/2022 TOC levels below 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
11/28/2022 TOC levels above 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
11/25/2022 TOC levels below 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
11/24/2022 TOC levels above 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
11/19/2022 TOC levels below 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
11/18/2022 TOC levels above 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
11/11/2022 TOC levels below 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
11/5/2022 Treatment Changes: Poor influent water quality (due to heavy rains) required an increase in the dosage of Chlorine. Additionally, increases in raw water turbidity and organic matter incoming to the plant required an increase in the dosage of Aluminum Sulfate (Alum). Lastly, the dosage for filter aid polymer briefly exceeded the trigger level of 0.2 mg/L for approximately 30 minutes before falling below the notification level once again. This notice is for industrial purposes only.
11/1/2022 TOC levels above 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
10/29/2022 TOC levels below 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
10/22/2022 TOC levels above 1.0 ppm due to recent weather events. This notice is for industrial purposes only.
7/7/2022 Treatment Changes: The dosage of Chlorine at the flash mix was increased to over 3.0 mg/L due to elevated raw water turbidity following routine maintenance of the raw water intake. Additionally, alum was increased (peaking at 50 mg/L) in order to handle the increased levels of raw water turbidity and organic matter. This notice is for industrial purposes only.
6/22/2022 End of Wapato Lake dewatering This is an annual occurrence that continues until the lake is fully drained. Pumping lasted 114 days. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
6/16/2022 TOC levels below 1.0 ppm. This notice is for industrial purposes only.
6/16/2022 TOC levels above 1.0 ppm. This notice is for industrial purposes only.
6/9/2022 TOC levels below 1.0 ppm. This notice is for industrial purposes only.
6/7/2022 TOC levels above 1.0 ppm. This notice is for industrial purposes only.
6/1/2022 Calibration of Powered Activated Carbon (PAC) feeder. Treatment change: Small amounts of PAC will be dosed early in the treatment process in the flash mix, prior to sedimentation basins. Pre-chlorination to the flash mix will be suspended during this time. This notice is for industrial purposes only.
4/6/2022 TOC levels below 1.0 ppm. Treatment Change: Caustic Soda added to Rapid Mix, due to changes in raw water chemistry This notice is for industrial purposes only. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
3/26/2022 TOC levels above 1.0 ppm. This notice is for industrial purposes only.
3/2/2022 TOC levels below 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
3/1/2022 TOC levels above 1.0 ppm due to recent weather event. Treatment Change: Alum dosage above 40 mg/L, due to increases in raw water turbidity and levels of organic matter This notice is for industrial purposes only.
2/28/2022 Start of Wapato Lake dewatering This is an annual occurrence that continues until the lake is fully drained, approximately 3-5 weeks. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
2/27/2022 Treatment Change:  Caustic Soda added to Rapid Mix, due to changes in raw water chemistry The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
1/13/2022 Treatment Change:  Caustic Soda no longer being added to Rapid Mix due to improvements in raw water chemistry The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
1/4/2022 TOC levels above 1.0 ppm. This notice is for industrial purposes only.

2021

12/21/2021 TOC levels below 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
12/12/2021 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
12/11/2021 Treatment Change:  Caustic Soda added to Rapid Mix due to changes in raw water chemistry The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
11/24/2021 TOC levels below 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
11/20/2021 Treatment Change:  Caustic Soda no longer being added to Rapid Mix due to changes in raw water chemistry The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
10/21/2021 TOC levels above 1.0 ppm due to recent weather event. Treatment Change: Caustic Soda added to Rapid Mix due to changes in raw water chemistry This notice is for industrial purposes only. The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
9/18/2021 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
6/3/2021 pH level for finished water leaving the water treatment plant briefly exceeded the notification trigger level of 8.7 mg/L (peaking at 9.39 mg/L) due to an additional caustic soda pump starting unintentionally. pH is back to normal levels. This notice is for industrial purposes only.
5/19/2021 pH & Chlorine levels for finished water leaving the water treatment plant were briefly elevated due to two filters being brought back online. This notice is for industrial purposes only.
5/18/2021 End of Wapato Lake dewatering This is an annual occurrence that continues until the lake is fully drained. Pumping lasted 98 days. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
4/24/2021 TOC levels below 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
4/6/2021 TOC levels above 1.0 ppm due to recent weather event. This notice is for industrial purposes only.
2/23/2021 Start of Wapato Lake dewatering This is an annual occurrence that continues until the lake is fully drained, approximately 3-5 weeks. This pumping can affect water quality entering the JWC water treatment plant and may result in treatment changes to maintain finished water quality.
2/7/2021 Treatment Change:  Caustic Soda no longer being added to Rapid Mix due to changes in raw water chemistry The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
2/5/2021 Treatment Change:  Caustic Soda added to Rapid Mix due to changes in raw water chemistry The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
1/17/2021 Treatment Change:  Caustic Soda no longer being added to Rapid Mix due to changes in raw water chemistry The addition of caustic soda occurs early in the treatment process and is not likely to have a negative effect on finished water quality. However, any change to the treatment process has the potential to impact industrial processes.
1/14/2021 TOC levels above 1.0 ppm due to recent weather events. Treatment Change: Alum dosage above 40 mg/L, due to increases in raw water turbidity and levels of organic matter This notice is for industrial purposes only.