June 19th Water Plant Manganese Issue

On June 19, 2026, at approximately 9:00 a.m., I received a text message from the water plant operator about a high in-house manganese reading at Water Plant 1. Initial testing showed a raw influent amount of .171 mg/L (mg/L = parts per million) and a finished water result of .077 mg/L. The EPA’s MCL (maximum contaminant level) for manganese in finished water is .05 mg/L.

Upon arriving at the water plant, I retested the influent and effluent water to verify the results. After confirming the results, I immediately began making operational adjustments to control the manganese coming into the water plant.

The issue with our water plant is that once I make an adjustment, it takes at least an hour to know if the adjustment that I made was correct. Throughout the day, I continued to monitor the finished water coming out of plant 1. Even though it was still high, the water from plant 1 was blending with plant 2 water that was making the amount of manganese in the water less. After several adjustments throughout the day, the manganese issue was not subsiding. I directed an operator to collect samples from the district’s 2 storage tanks. Once I got those, I performed an in-house test of the manganese and Rio Oso tank was showing almost a non-detect amount of manganese (.01 mg/L), but Van Vleck tank showed a .04 mg/L.

Because the VanVleck tank getting close to the .05 mg/L amount, I put plant 1 to waste. Due to the way both of our water plants were designed, if I have to waste plant 1, I have to turn off plant 2 completely. Because of the amount of manganese showing in Van Vleck tank, and out of an abundance of caution, I contacted Amelia Wilder and John Merchant to inform them of the situation and requested public notification be issued to District residents. I felt it was better to do that while I was trying to resolve the issue. Not knowing how long or how bad this manganese flare-up was going to last or how long it was going to take me to get it under control, I made this decision out of concern for the Districts residents.

I also contacted the District's engineer to seek assistance from a chemical engineer experienced in water treatment. The engineer connected me with a chemical engineering consultant. After reviewing the situation and the corrective actions already underway, the consultant advised that I was taking the appropriate steps but needed to implement them more aggressively. Once those recommendations were put into practice, manganese levels began to improve.

At approximately midnight, the levels of manganese came down significantly and I was able to put the water back into the system. I continued monitoring manganese levels until about 8:00 a.m. on Saturday morning. Once I was confident that we had taken care of this flare-up, I notified Amelia Wilder and Board members that the situation appeared to be under control and recommended that an all-clear notification be issued.

The levels in the storage tanks never hit the .05 mg/L exceedance based on in-house testing. The final reads that were taken from the tanks were Rio Oso’s highest level reached .01 mg/L and Van Vleck’s highest level was .04 mg/L. Again, the decision to issue a public notification was made out of an abundance of caution in the event conditions worsened.

This was a flare-up of manganese higher than I have seen in the past, not the normal. Sunday morning samples were tested from both tanks and the water plant and the testing showed that Rio Oso tank had a .006 mg/L amount (practically zero manganese), Van Vleck showed .021 mg/L of manganese. Water plant 1 finished water from plant 1 and 2 was nondeductible amounts of manganese.

I send out samples to our lab multiple times a week for testing to ensure good water quality. The issue is that it takes two days to get the results back. I don’t know why this flare-up happened, but I will always make the best decisions that I can to ensure the safety of the residents of Rancho Murieta.

Sincerely,
Travis Bohannon
Chief Plant Operator

Many of you received an alert the evening of Friday, June 19, stating that the Manganese levels in the water had reached the EPA's maximum contaminant levels. The alert has been lifted and it is safe to resume using the water as Normal. While you shouldn't have any brown water, if you do, flush your lines for 10 minutes until clear. If the issue does not clear within 10 minutes, please contact the district on Monday, at 916-354-3700, and we will flush the lines. We plan to post a report with details on what happened Monday.

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Original Message: Precautionary Alert Manganese Levels are at EPA’s maximum contaminant levels. Infants and Babies should be given bottled water until further notice.