An historic Penryn industrial site being redeveloped to provide new homes has been given the all-clear by the Environment Agency after a major remediation programme.

Where 43 modern flats are now taking shape off College Hill, the old Penryn Gasworks once provided energy for the town for nearly a century after being commissioned around the 1870s. The site also housed the former Penryn Laundry for many years.

Construction of Lowena Homes' "Newport" complex began a year ago following completion of initial remediation works, costing £200,000, to decontaminate and remove toxic substances including cyanide and arsenic from the soil.

But the Redruth-based developer has since had to spend another £150,000 on further remediation works, lasting nearly two months, following the discovery of contaminated water at a depth of 14 metres once construction was under way.

The discovery came after the demolition of the buildings latterly occupying the site - Evans Cash and Carry warehouse and a mill once operated by P Dawe and Sons Holdings Ltd.

Lowena Homes construction director Alec Bawden explained: "While these old buildings were still there, the rock below was compressed, but the demolition led to the opening up of fissures which released hydrocarbons into the water courses and caused a serious headache for us.

"Now that we have constructed the new buildings, the rock has become compressed again and in the meantime we have extracted and filtered huge quantities of contaminated ground water.

"We were amazed to discover that the pressure of buildings above rock could have such implications under the ground, but now we can say we have well and truly removed a less than welcome legacy of our forefathers."

Nearly a thousand cubic metres of groundwater was pumped up from four treatment wells installed on the site, yielding 33 kilograms of hydrocarbons. The clean water was reintroduced into the drainage system after the filtering process.

The remediation works were undertaken by London-based RPS Health, Safety and Environment.

The entire Newport project is scheduled for completion by the end of the year and there are now just five flats still for sale, priced from £129,950 to £165,950.