A housing developer must stop work on a site in eastern Newport over concerns “harmful” substances could enter a protected conservation area in the Gwent Levels.

Newport council’s planning committee voted unanimously on Wednesday to serve a breach of condition notice on Bellway Homes, to cease work at Phase 4H of the Glan Llyn site, in Llanwern. 

The committee heard officers had flagged the presence of substances which are “harmful to health and the environment”.

The development boundary is around 550 metres from a waterway called Monk’s Ditch – part of the wider Gwent Levels and a site of special scientific interest (SSSI).

The council argues that its efforts to resolve the matter have effectively been ignored, and work is continuing at the site despite its assertion the developer is breaching a condition of its planning permission.

Bellway bought the freehold to the Phase 4H site from St Modwen Developments – the “master developer” of Glan Llyn – in 2021 and has its “full ownership and control”, Joanne Davidson, the council’s east area development manager, said.

Outline planning permission for the site had already been agreed, subject to conditions including that “remediation works” of sampling and groundwater quality monitoring be carried out at each stage of development.

Newport Council has alleged that work to build houses on the site “is continuing without the discharge of” that condition.

Ms Davidson said “tars, heavy metals and petroleum-based oils and fuels” are present there due to the “long industrial legacy” of the wider site, which used to house a steelworks.

These substances need “appropriate management and remediation”, she added.

Ms Davidson said officers asked Bellway in January to cease building work on the site until the remediation works were sufficiently completed, but the developer “did not stop and indicated to us that they would not stop”.

“Pumped water from the site will directly enter the SSSI,” Ms Davidson said. “If the site introduces contaminated water to Monk’s Ditch, it threatens the quality of the protected habitat.”

Pete Sulley, the director of Asbri Planning, spoke at the meeting on behalf of Bellway.

He defended the developer’s record of house building in Newport and challenged the council’s claims about dialogue between the parties.

Mr Sulley said officers “consistently refused” requests to meet, and said a council claim – which described attempts to resolve the matter informally as being unsuccessful – is “unfair”.

Any material at the Phase 4H site would “literally take thousands of years” to reach waters protected by the SSSI, he added.

But Ms Davidson told the committee the council had been “dealing with” the master developer for “well over two years for Phase 4H” before Bellway started work on the site, and Bellway would have been able to view documentation on the matter.

Natural Resources Wales “continued to raise objection” to work going ahead, Ms Davidson said, adding that ongoing construction at the site is “highly prejudicial to the resolution of this, in our view”.

Several committee members spoke in support of the council’s request to serve a breach of condition notice.

Cllr Mark Howells said it seemed a “pretty straightforward issue”, adding he was “frustrated with developers rocking up here, thinking they can ride roughshod over the planning system and expect us to roll over”.

Bellway now has 28 days to stop work at the site, and cannot resume until the council is satisfied with the remediation works.

Failure to stop work would be an offence and could lead to further penalties and prosecution, Ms Davidson said.

Following the committee’s decision, a spokesperson for Bellway Homes said: “As a responsible developer, Bellway always looks to adhere to all the planning conditions set on our developments. 

“In the case of our Glan Llyn development, we have been attempting to work with the local authority and other stakeholders to resolve this matter to satisfy the condition set, but have faced obstacles in doing so.

“As a result of today’s decision, we will continue to work to resolve this as a matter of urgency.”