In 2014, the EPA stipulated that the maximum contaminant level (MCL) for hexavalent chromium in drinking water should be no more than 10 micrograms per litre. This effectively put many public water systems in California out of compliance, creating demand for an affordable, safe and effective solution to lower contaminant levels to meet the new requirements.
Höganäs conducted a pilot study to demonstrate the effectiveness of its Cleanit LC technology at a difficult to treat well in the Californian city of Los Banos.
Cleanit LC creates a highly reductive environment reducing chromium 6, which can be carcinogenic, to chromium 3, making it safe to drink. The chromium 3 then attaches itself to a bed of iron composite especially engineered for water treatment – in short, its porous surface structure is able to hold more contaminant allowing it to react and reduce. This stable bond effectively rids the water of contaminants to non-detect levels, leaving a media bed that is non-hazardous.
The pilot study was so successful that the California Water Boards’ Division of Drinking Water (DDW), a globally respected environment agency, awarded Cleanit LC technology conditional approval in 2018. Unlike other treatment processes, Cleanit LC is especially cost-effective because it doesn’t produce a concentrated, hazardous waste stream that requires further treatment and is difficult to discard. In fact, the remaining powder can even be re-used by Höganäs.
The pilot study is just the start. Despite a delay in the enforcement of the MCL, Cleanit LC technology is ready to be implemented at the Los Banos site when the new limit comes into force in 2019. It’s likely that other public water systems in California will adopt this solution thereafter.
Other Cleanit LC benefits include:
- The operation is simple and cost-effective, and it doesn’t require as many chemicals when compared to existing treatment methods
- As Cleanit LC removes contaminants to non-detect, it’s possible to mix streams of treated and untreated water and still meet compliance levels
- It’s a future-proofed solution – even if the MCL is lowered, Cleanit LC treated water will always be compliant as it achieves non-detectable contaminant levels
- If recycling isn’t an option, the non-hazardous powder ‘waste’ does not require treatment and can be disposed of safely
- Multiple contaminants – not just chromium 6 – can be removed in one step
- The process is less labour intensive – it can be automated and does not require daily maintenance