Exclusive: Investigation into Erin Landfill near Chesterfield reveals breaches, structural issues and ‘significant risk’ to offsite odour

The Derbyshire Times has analysed 20 Environment Agency (EA) reports issued for Erin Landfill site in Duckmanton in the first six months of 2026 - with our investigation revealing a number of issues and breaches.

The reports issued at the beginning of the year included an overview for 2025 with the annual monitoring review issued in February revealing that Erin Landfill site removed over four times more leachate in 2025 compared to 2024.

Leachate is defined as contaminated liquid that forms when water filters through waste.

Commenting on the leachate levels, which quadrupled in 12 months, a Valencia spokesperson said: “Managing leachate is a core part of operating landfill sites in accordance with their environmental permit.

"Leachate is mainly produced by rain falling on wastes in landfill sites and inter year variation in volumes is normal and to be expected for any operational landfill.

"2025 was a particularly wet year and the site operations responded accordingly.”

The EA document, further revealed that in 2024 Valencia removed 3,154 m³ of leachate of its site but in 2025 this increased to 14,578 m³.

The document further reveals that 19 094 772Nm³ of landfill gas was combusted in gas engines in 2025 - an increase from 16 599 622Nm³ in 2024.

Commenting on the increased gas levels, a Valencia spokesperson said: “Landfill gas is generated from the decomposition of landfilled waste within engineered landfill cells.

"Depending on the composition and quantity of the waste within the landfill site gas will be generated at varying rates throughout the life of a landfill site.”

Annual Monitoring Report for 2025 issued on March 31, revealed further concerns - with four instances of nickel levels in groundwater recorded above the compliance limit.

Nickel can have negative impacts on the environment and human health, with the health impact depending on several factors, including the amount to which someone is exposed, the way they are exposed, the duration of exposure, the form of the chemical and if any other chemicals were also present.

While the document does not reveal the exact amount of nickel found, this was recorded as a C3 (Category 3) breach - a non-compliance associated with a minor impact on human health, quality of life or the environment.

The Derbyshire Times asked Valencia why nickel compliance limits were exceeded and if the operator can reassure residents living nearby that this did not pose risk to their health.

In response, a Valencia spokesperson said: “It is vitally important to monitor and protect the local ground water around our site.

"This particular monitoring location is upgradient of the landfill site and isn’t influenced by onsite activity.”

The EA has raised further concerns in regards to breaches at Erin landfill site in 2026.

In the report based on this year’s first compliance site inspection carried out on February 12, while proceeding up the haul road on Cell 4, an EA inspector observed an area of damaged cap.

The landfill site manager informed the EA that the damaged section formed a part of the temporary cap and said that permanent capping would be completed once conditions improved.

However, the EA said that at this point the temporary cap had remained in place for over a year.

The Environment Agency further raised concerns that prolonged exposure to weathering conditions at the damaged temporary cap was ‘likely to compromise its structural integrity’.

Asked why a temporary cap was in place for over year, a spokesperson for Valencia said: “We operate the landfill site with phased capping and restoration activities on an ongoing basis.

"Temporary capping is designed to minimise gas emissions as far as possible, without the cap we would have more emissions.

"Permanent capping will be conducted when the site is engineered to accommodate this work and there is availability of geo-engineering teams.”

The EA reports have revealed that in the first six months of 2026, Valencia accumulated 86 Compliance Classification Scheme (CCS) points for Erin landfill site breaches recorded by the Environment Agency.

The EA CSS points are handed out to operators if they breach their permit conditions and are divided into four categories – including 60 points for any Category 1 (C1) non-compliance, 31 points for C2 non-compliance, four for C3 non-compliance and 0.1 point for C4 non-compliance.

The scores accumulated during the compliance year (January to December) are later added together to generate a compliance band - with A being the best and F the worst.

The higher the compliance band the greater the operator's subsistence rate for the following year.

Erin Landfill site, which was a band D operator in 2025, has accumulated enough CSS points in the first half of 2026 to be classified as a band E operator meaning Valencia will need to pay at least 150% subsistence rate in 2027.

The Derbyshire Times asked Valencia why the landfill was given more CCS points in the first six months of 2026 than throughout the entire 2025.

In response, a Valencia spokesperson said: “The Environment Agency monitor and regulate the site in accordance with its

Environmental Permit, CCS scores are given for observations across the site.

"The Environment Agency attend the site on announced and unannounced visits.

"We are committed to operating our landfill at Erin to the highest standards and are continually investing across the site to maintain compliance.”

Valencia did not explain why the operator received more CCS points in the first six months of the year than in the previous 12 months.

The operator did not confirm what action it was going to take to prevent further breaches this year.

The EA documents show that among the most serious breaches recorded in the first half of the year were two C2 non-compliances in relation to construction of Cell 6 – resulting in 31 CCS points for each non-compliance.

The breaches relate to structural issues with the EA reporting ‘presence of liner movement, creasing, and uneven support’ which ‘increases the risk of stress cracking of the geomembrane and subsequent leakage rates’.

The EA noted that liner bouncing indicated ‘trapped water or air beneath the liner’ raising concerns.

The report states that observations on site suggest ‘engineering works’ were ‘not carried out according to the approved CQA plan’.

The Derbyshire Times asked Valencia to provide reasons for these breaches, explain what actions have been taken in response to the report and what changes the operator would implement to similar breaches do not occur in the future.

Valencia did not answer any of these questions.

During an inspection carried out at the end of May, the EA observed presence of ‘cobble and boulder sized particles included into the geological barrier’.

The report states: “The presence and number of these oversized inclusions would suggest that there was a lack of vigilance during the construction of the geological barrier both by the CQA ( Construction Quality Assurance) Inspector and the earthworks contractor.”

Valencia was advised to remove the oversize and work the material to allow the soils to dry before being graded and compacted.

The Derbyshire Times asked Valencia why the works on Cell 6 were of such poor quality and if the operator has investigated concerns raised in relation to the quality of work carried out by CQA Inspector and the earthworks contractor.

We further asked what steps have been taken since to ensure that Cell 6 met the criteria required by the Environment Agency.

A Valencia spokesperson said: “We were disappointed with the Environment Agency’s findings from a routine inspection.

"This part of the site was not being used for waste activities at the time.

"Constructing a new landfill cell is a significant piece of engineering and weather conditions can impact this work.

"The Environment Agency are required to sign off on new landfill cells and following this feedback we undertook works to respond to their comments and soon afterwards the new cell was approved by the Environment Agency.”

The EA further observed that the membrane on the anchor trench was ‘poorly formed causing the geomembrane to be rumpled’ and noted that the anchor trench depth was ‘inconsistent and the geomembrane did not extend fully down the front face and across the base of the trench’.

More concerns were raised at the beginning of June when a Compliance Assessment Report (CAR) revealed that a side riser posed a ‘significant risk to offsite odour occurrence’.

The report reads: “The side riser poses a significant risk to future offsite odour occurrence.

"As such we see it as an environmental priority, to ensure that adequate gas collection infrastructure and management procedures are in place prior to commencing landfilling.”

Asked if any action has been taken to resolve the issue and minimise the offsite odour occurrence, a Valencia spokesperson said: “Valencia invests significantly, and on an ongoing basis to install new gas wells, piping infrastructure, and equipment to enhance the gas capture and collection rates across the site.

“We have undertaken works to enhance the side riser quality including the installation of a new gas main pipe 39 new gas collection wells in 2026.”

A planned site inspection on June 15 further revealed issues with Cell 3 – where a previously identified landslip was found unrepaired.

Valencia confirmed that the landslip was now repaired.

A spokesperson said: “The landslip has now been repaired as part of the wider landfill landscape engineering works taking place over the summer.

"During certain seasons and weather conditions it is not possible to undertake substantial landscaping works.

"This is now awaiting Environment Agency approval.”

Further inspection carried out on June 23, in response to an increase in complaints from nearby residents regarding flies, odour, and dust, found a pile of uncovered waste consisting of foam material.

In the inspection report the EA highlighted that foam ‘can provide a potential breeding environment for flies’ and urged Valencia to cover the waste.

A low number of flies were observed during the EA visit.

An EA inspector observed that one area which had previously received waste appeared to require additional cover – and warned without adequate cover it could cause a number of issues including odour, flies and increased pollution.

The report reads: “Inadequate cover can allow flies continued access to biodegradable waste, creating favourable breeding conditions and increasing the potential for off-site nuisance.

"It may also contribute to odour generation, litter dispersion, and the attraction of birds and vermin, resulting in an increased risk of pollution and adverse impacts on local amenity, including complaints from nearby receptors.”

Some dust was observed being generated by operational vehicles transporting waste to the tipping face.

The landfill site manager advised the EA that a water bowsers was deployed approximately every hour to help manage dust levels, but it was not observed operating during the 55-minute long inspection.

The inadequately covered waste and increased amount of dust were identified during an inspection carried out just a week before July – when the EA received over 300 complaints from nearby residents raising concerns over ‘horrendous’ smell, ‘fly infestation’ and issues with dust across Poolsbrook and Duckmanton.

The Derbyshire Times have asked Valencia why the foam material was not covered as required and if it was secured with an adequate cover before July.

A Valencia spokesperson said: “When materials that are not part of our normally incoming waste stream are delivered it is sometime necessary to isolate them for a short period.

"This will enable us to engineer suitable void space for them to be tipped into the landfill. Or should they be non-conforming waste to enable us to remove them offsite to an appropriate licenced facility.”

Commenting on the high number of complaints in July, a spokesperson added: “We recognise that flies are a significant concern to the local community.

"We employ a pest controller, have installed traps onsite, and monitor on an ongoing basis.

"At no point in the last 12 months there have been no issues with flies reported onsite by the Environment Agency.

“As has been discussed at the recent community meeting the odour issue over the summer was the result of engineering works that exposed aged waste during excessively warm weather.

"We have recognised that this was not the right time to undertake this activity and have apologised to the local community.

"We recognise that the landfill site is close to homes and focus on operating in a sensitive way.”