Rialto’s Arsenic Levels Near Legal Limit in Drinking Water: Council Challenges Veolia’s Water Safety Protocols

Arsenic levels in Rialto’s drinking water have raised concerns after City Well 2 registered arsenic concentrations of 9.7 parts per billion (ppb) in March 2023, just shy of the federal maximum contaminant level (MCL) of 10 ppb. During a contentious City Council meeting, Mayor Pro Tem Ed Scott questioned Veolia, the city’s water service provider, on their decision to keep the well operational and expressed doubts about the safety measures taken to protect the public.

“We should be looking at shutting that well down, period,” Scott asserted, after Veolia’s representative claimed that blending the water with other sources mitigated the high arsenic levels. “All that is, is dilution, and that is not acceptable.”

According to Stephen Difuccia from the Rialto Utilities Department, arsenic was detected in the city’s annual Consumer Confidence Report, which is mandated by the Safe Drinking Water Act. This report indicated an increase in arsenic concentrations from an average of 0.52 ppb in 2020 to 6.7 ppb in 2023, with a peak reading of 9.7 ppb when Well 2 was brought back online after three months of inactivity.

Veolia’s defense hinged on the argument that the arsenic levels, while elevated, remained within the legal limits. A Veolia spokesperson explained that the high arsenic reading was an “anomaly” due to the well being offline for an extended period and insufficient flushing before sampling. Subsequent tests showed levels stabilizing to around 5 ppb, well below the legal threshold.

Despite these assurances, Scott pressed the issue, asking Veolia what percentage of the city’s water comes from Well 2 and why alternative water sources weren’t prioritized. Veolia failed to provide immediate answers, which only further fueled skepticism.

“Why did we not shut the well down and pump from other areas?” Scott demanded. The Veolia representative reiterated that the well’s arsenic levels had not exceeded the MCL and that shutting down Well 2 was unnecessary, sparking further debate over the safety of the city’s water supply.

Councilmember Rafael Trujillo added to the scrutiny by raising questions about lead contamination. Veolia assured the council that Rialto’s lead levels were “non-detect across the city” and highlighted ongoing efforts to inventory and replace lead pipes in the system, with more updates expected by October 16.

Veolia’s report, detailed in the 2023 Consumer Confidence Report and PowerPoint presentation, emphasized that arsenic is a naturally occurring semi-metal found in soil, sediment, and groundwater. The company reassured residents that Well 2 water is blended with arsenic-free water from other sources, maintaining overall safety.

However, the report also acknowledged that the public health goal (PHG) for arsenic is as low as 0.004 ppb, far below the MCL of 10 ppb. While the PHG represents the safest level, achieving zero arsenic in drinking water is not always feasible due to the element’s natural occurrence.

Rialto’s partnership with Veolia dates back to 2012, when the city entered into a 30-year concession agreement with Rialto Water Services (RWS) to manage water and wastewater systems and undertake significant infrastructure improvements. Veolia is responsible for delivering all water and wastewater services under this agreement.

The next quarterly arsenic sample is expected in September, with council members and residents closely watching to see if the levels remain stable or increase again.

For further information, Rialto residents can view the full Consumer Confidence Report on the city’s website or request a hard copy through their water bill.