People endured a third day without water following a fault with a supply facility.

Southern Water customers in West Sussex who received their water from the Upper Nash and Itchenfield reservoirs experienced low pressure or no supply at all following a failure at the Hardham Water Supply Works near Pulborough.

The site was shut down late on Saturday night, with as many as 40,000 homes left without water on Sunday afternoon.

Residents in Horsham, Billingshurst, Pulborough, Rudgwick, Barns Green and Slinfold all reported issues with supply due to the fault, which was caused by “unusually low levels of chlorine”.

Southern Water was forced to open bottled water stations across the county, with some staff delivering bottles to the worst affected addresses and the homes of vulnerable people.

Cars queued up at some stations as residents rushed to collect supplies.

The Argus: Cars queued at one collection station as residents waited for bottled waterCars queued at one collection station as residents waited for bottled water (Image: Sussex News and Pictures)

A fleet of 19 tankers supported hospitals and supply where it was needed as residents and local services struggled due to the outage.

More than 10,000 customers in Crawley, Turners Hill and East Grinstead were reportedly without water last night and, although many had their service restored yesterday morning, the fault continued to have an impact on others.

Seven schools in West Sussex were forced to close and there was disruption for commuters at Three Bridges railway station.

Meanwhile, in order to avoid disruption to GCSE exams, which began yesterday, Southern Water ensured that a secondary school in the affected area had a “direct supply” of water.

A spokesman for the company said the large area affected and the “cautious approach” needed to fix the fault caused the restoration of supply to take “a little longer than expected”.

Customers who get their supply from the Itchingfield reservoir are still without water but pressure is said to be improving.

Affected homes are having bottled water delivered directly to them due to the length of time they have been without water. Tankers are being used to help.

Bottled water stations were open for a second day in Crawley and Horsham, with the K2 Leisure Centre being used as one of the hubs for those affected by the outage.

The spokesman said: “Our sites operate to the strictest standards for water quality and are designed to automatically shut down well in advance of any risk to our customers.

“The incident was caused by unusually low levels of chlorine being detected at our Hardham Water Supply Works.

“Chlorine is an important part of our standard treatment processes used to ensure water quality meets the very high standards.

“We would like to apologise for the inconvenience this situation caused over the weekend and thank our customers for their patience as we work to fix the issue and return water supply.”

Vulnerable customers who need access to bottled water as a priority can call Southern Water on 0330 303 0368.