Residents in several areas served by the Cheam Water Treatment Works are currently experiencing increased water hardness, and the issue is expected to continue until the end of October.

SES Water, which supplies water to parts of Cheam, Sutton, Worcester Park, Ewell, Morden, Carshalton, Carshalton Beeches, and South Sutton, has acknowledged that repairs to the softening system at the treatment works are taking longer than anticipated.

Water hardness refers to the presence of dissolved minerals such as calcium and magnesium in the water, which can cause limescale deposits on household appliances and surfaces.

While SES Water assured customers that the increased hardness poses no health risks, it may result in noticeable changes in everyday water use.

For example, customers might observe more limescale build-up in kettles, glassware, and on taps, as well as a film forming on cups of tea or cordial.

The company has emphasized that this change is temporary and related to repairs underway at the Cheam Water Treatment Works. “The work required is complex,” SES Water explained, “and will require more time than initially thought to fully fix the issue.”

Water softening is expected to resume by the end of October, at which point the water hardness will return to normal levels.

SES Water is one of the few water suppliers in the industry with a legal obligation to soften the groundwater it treats. In recent years, the company has made significant investments to improve its softening capabilities.

Despite this, the current repairs were deemed necessary, leading to the temporary halt of the softening process.

The Drinking Water Inspectorate (DWI) recently confirmed that the company’s water quality remains among the best in the industry.

SES Water reassured customers that, despite the increased hardness, the water remains safe to drink and use as normal.

For residents concerned about how the change affects their daily routines, the company has provided detailed information about the water's hardness during the disruption. For example, calcium levels have risen to 132 mg per litre, while calcium carbonate levels are now at 330 mg per litre.

This may mean residents need to adjust their dishwashers or other appliances to account for the change.

In response to concerns from customers, SES Water confirmed that they would not be offering direct compensation for the inconvenience.

However, the company noted that any financial penalties resulting from not meeting softening targets will be deducted from next year’s revenue, potentially leading to lower bills in the future.

SES Water has also addressed concerns about under-investment in infrastructure, insisting that the necessary repairs are routine and unrelated to the company's recent acquisition by the Pennon Group.

They emphasized that water softening remains a priority and that substantial capital investments have been made to maintain and improve their softening systems over the years.

The company apologized for the ongoing disruption and reassured customers that they are working as quickly as possible to restore normal water hardness levels.

Residents seeking more information are encouraged to visit the SES Water website or contact their Extra Care team for additional support.