The City of Modesto, serving over 218,000 residents, has been monitored under the EPA's Unregulated Contaminant Monitoring Rule 3 (UCMR3) for chromium-6, also known as hexavalent chromium or chromium(VI). Between 2013 and 2015, 126 water samples from Modesto's surface water supply system were tested, with 124 registering chromium-6 above the reporting threshold of 0.03 micrograms per liter (µg/L), reaching a maximum recorded concentration of 7.0 µg/L and a median detected level of 2.65 µg/L. These findings reflect the presence of chromium-6 in the public water system but do not identify any health-based violations by the EPA or federal standards.
If You Want to Understand What the UCMR3 Survey Means for Your Household Water
The UCMR3 survey is a federal effort to gather occurrence data for contaminants not yet regulated by maximum contaminant levels (MCLs). Its sampling is system-wide and does not assess individual homes. Therefore, while it provides valuable insight into regional water quality, it cannot pinpoint chromium-6 levels in your home's tap water, especially if your water treatment equipment has ceased functioning. To determine your specific chromium-6 concentration, a direct water test is necessary, as regional data cannot substitute for localized analysis.
If You Consider Total Chromium Results Instead of Chromium-6 Alone
Total chromium measurements combine chromium-6 with trivalent chromium (chromium-3), which behaves differently in water and biological systems. The Modesto system recorded total chromium levels with a maximum of 7.5 µg/L and a median of 2.65 µg/L, mirroring chromium-6 detections closely. However, total chromium data alone cannot distinguish the potentially more reactive and mobile chromium-6 fraction. Therefore, when specifically addressing chromium-6 concerns, it is vital to focus on hexavalent chromium measurements rather than total chromium.
If You Are Wondering Why California Applies a 10 µg/L Benchmark for Chromium-6
California has established a public health goal of 10 µg/L (parts per billion) for chromium-6 in drinking water based on state-specific risk assessments. This threshold guides water system management and consumer advisories within California but is distinct from federal regulations, which do not currently set an MCL for chromium-6. Understanding this helps households elsewhere recognize that state limits reflect local policy and research and that presence below this benchmark does not necessarily imply a health risk or regulatory violation.
If You Are Concerned About Long-Term Effects of Untreated Chromium-6 in Household Water
Prolonged exposure to chromium-6 without mitigation may contribute to aesthetic issues such as metallic taste or discoloration, though federal records show no health-based violations for Modesto's water system. Scientific understanding of chromium-6's health effects continues to evolve, so households experiencing equipment failure should consider water testing and consult with water treatment options. Addressing chromium-6 proactively can help maintain desired water quality and peace of mind.
If You Want to Know the Maintenance Rhythm for the Autotrol Chromium-6 Filter
The Autotrol Chromium-6 Filter ships ready to configure and uses technology designed to specifically address chromium(VI) in residential water supplies. Its operation involves regular upkeep to maintain effectiveness, typically aligning with operational schedules established by the product guidelines. Users should monitor system performance periodically and renew filter media as indicated by water quality changes or manufacturer recommendations. This ensures continued management of chromium-6 following water treatment equipment failure.
In summary, Stanislaus County's monitoring reveals detectable chromium-6 in Modesto's public water system but no federal health-based violations. Households facing treatment equipment failure should pursue water testing to understand their individual chromium-6 levels and consider the Autotrol Chromium-6 Filter as a documented technical solution to sustain water quality in their homes.
Where this information comes from
Source: EPA SDWIS public water system record. Sampled 2014-02-06. These figures describe the public water system's record, not the plumbing inside any individual building.
On record: EPA UCMR3 monitoring (2013-2015) for City of Modesto (CA5010010), CA: 252 results across 2 listed contaminants, 238 detections above the reporting level; no federal MCL for hexavalent chromium; total chromium MCL 100 ug/L
- ✓ 90-Day Money-BackNo restocking fees — return within 90 days.
- ✓ Manufacturer WarrantyGenuine Fleck · Pentair · VIQUA equipment.
- ✓ Free Expert SizingTalk to a specialist and buy the right system the first time.