RESIDENTS’ fears that infill packed into holes which opened up last year on an open space contained toxic material have been allayed after tests confirmed there is no contamination.

But neighbours of Bernards Heath in St Albans are annoyed that the once relatively-level field long-used to play informal football and other activities still looks like “a moonscape” because of 60cm-high mounds of earth placed on the cavities.

Herts County Council recently investigated material used to fill holes which formed after land subsided on the Heath’s lower field last year. With the area historically excavated in part to extract clay for the local brickmaking industry over a 400-year span, subsidence is apparently an ongoing problem.

Sub-contractors originally used substandard fill containing some asbestos debris but that was removed following complaints and replaced with new infill, which was checked before being laid to ensure it was up to standard.

According to the chairman of Friends of Bernards Heath, Peter Cook, visitors to the site were concerned that the original, substandard, infill contained rubbish such as glass, broken toys and other items.

Following an allegation that a dog digging a filled-in cavity had been accidentally poisoned by something placed in one of the holes, fences were put around the area as a precaution, the infill was removed and replaced and contamination tests undertaken.

A spokeswoman for the county council said: “Samples were taken on July 12 and we got the results on August 3. The results confirm that there is no contamination.

“We will now take down this inner fencing in the next couple of weeks. Then we plan to do a surface pick of stones and debris across the whole area and the outer fencing will then come down, hopefully by the end of the summer holidays. In September we will carry out a further surface pick, then clear the weeds before putting down grass seed.”

Peter said while he was “absolutely relieved” the tests showed no contamination, fellow residents remained “deeply concerned” that the much-loved lower field had been left, “disfigured by large heaps of soil. We are left with this weird, surreal landscape.”

He explained: “The old claypits were used as rubbish dumps in the early years of the 20th-Century until the field was bought by the county council after the Second World War, levelled and grassed over.”

He described the council’s recent infill project as a mess: “The earth mounds on the field are at least two feet high, which is obviously too much; there is no chance that they will settle down to become level with the original surface.”

Peter Bone, senior surveyor for Lambert Smith Hampton, the county council’s consultants on property issues, confirmed that, “long-term, it may potentially take decades for the mounds to settle.”

Mounds were placed on the cavities as there was concern that further subsidence and additional holes could develop because there was chalk beneath the site, which could be dissolved by groundwater.

In a document written in July and placed on the internet about the controversial issue, Peter Bone said the question of possible contamination referred to historical infill, probably imported to the site during the 1940s and ’50s, when such things were little regulated.

In relation to the alleged poisoning of the dog, he said an initial subsoil survey, “did find some ash at depth in the historical infill, possibly resulting from burning animal waste from the old suet factory use, which could account for any phosphates that might be found to be present. There was also some evidence of contaminants at deeper levels.”

The weight of the mounding would eventually, “help to compact the subsoil”, he added.