Bosses at an historic Walsall foundry have spent £750,000 overhauling machinery to keep dust emissions down following a battle with residents.

The hefty bill is additional to the £1.09 million paid out by Chamberlin & Hill Castings Ltd in Chuckery after the long-running dispute was settled with its neighbours. People living on the nearby Crabtree estate complained dust from the firm was damaging their health and tests discovered high levels of PM10 particles, which can cause coughing and wheezing.

In extreme cases it causes lung disease. Tim Hair, chief executive of parent company Chamberlin Plc, said the business had spent £750,000 since 2001 on changing machinery and making general improvements to how it operates.

“We’ve made it cleaner,” he said. “We do try to be a good neighbour.”

Last week the firm opened its doors to the public as part of the national Heritage Open Days which sees buildings of historic importance laid bare.

Bosses took the decision to open the foundry in Chuckery Road to encourage a better relationship with people of the town. “When I arrived here I reached the conclusion immediately that we needed to tell people what we do,” said Mr Hair.

“This is an outstanding business. We need to tell the people who live around it so they understand what it does.”

The long-running dispute with residents came to end in June, but details of the settlement were kept under wraps with all concern asked to sign a confidentiality agreement.

The factory, which has operated since 1890 said the amount covered its own legal costs, together with the undisclosed offers made to claimants and their lawyers.

The firm neither accepted or admitted liability under the claims but decided to agree a settlement.

At its peak in the 1960s around 250 people were employed at Chamberlin’s which lies in between Beacon Street and Tong Street.

In the past six years the business has turned its been producing to cast iron core fittings for turbo chargers and supplies moulds for the best known car makers including BMW.

It once operated other sites in Reeve Street, Bloxwich, and in Beacon Street, in Lichfield, but both were closed by the company.