PLANS for thousands of home north of Dorchester may have been dealt a fatal blow by concerns from Wessex Water.

The public body says developing the site could put the area’s water supply at risk.

It became public yesterday when a “master planning” exercise was being held on the proposed development, an event which included local councillors and other stakeholders.

Conservatives on Dorset Council have backed the proposals for more than 4,000 homes in the next Local Plan  – despite widespread local opposition including from West Dorset MP Chris Loder, Dorchester councillors and Dorchester Town Council.

STAND, the group which has been spearheading the opposition, has welcomed the Wessex Water report and has called for Dorset Council to immediately suspend work on the development sighting the warning from the water company of “a significant negative impact on the quality of the town’s drinking water.”

Jane Ashdown, who chairs STAND (Save the Area North of Dorchester), says the water company’s concerns are a major blow to Dorset Council’s plans. She says work on the north of Dorchester proposal should be halted while Wessex Water carries out a major risk assessment of the impact of the development on water quality.

“Wessex Water says experience suggests that the existing borehole may have to be abandoned and alternative water supplies developed.

“Who is going to pay for water treatment when water quality is degraded by development or pay for new reservoirs?” asks Ms. Ashdown. “If Wessex Water foot the bill, then the costs are likely to be passed on to householders already struggling to cope with rising utility bills. If it’s the property developers who pay, house prices will have to go up and the dream of a truly affordable home will be beyond the reach of local families.”

“Dorset Council needs to stop investing public money on a proposal which appears to be unaffordable and which would cause huge environmental damage to the landscape of the Dorchester area,” she said.

Wessex Water in an email to the firm of consultant say the so-called “garden community” on fields and water meadows north of Dorchester could result in pollution of the Eagle Lodge borehole, which provides most of the Dorchester area’s drinking water. They say it’s likely that significant investment will be required to maintain the quality of the water supply including the provision of new reservoirs.

Dorset Council has been asked to provide a response to the Wessex Water statement and say whether or not it will affect its backing for the development – but at the time of publication had not responded.

The Wessex Water report reads:

“Wessex Water objected to this development through Local Plan consultation and is still not satisfied that risks to Eagle Lodge, a major strategic public drinking water supply source can be mitigated without significant investment.  We intend to commission our own Hydrogeological Risk Assessment and seek contribution via S106 obligations to protect the source from adverse, long-term groundwater quality impacts if this significant development is permitted in the Source Protection Zones of Eagle Lodge source.

The Wessex Water commissioned HRA will cover all potential water quality risks including their pathways to the underlying aquifer.  This is required so that WW can plan detailed contingency options for additional treatment to manage anticipated reductions in groundwater quality in the future.

The history of nitrate reduction in this catchment shows that land use change will affect groundwater quality in the long term.  In addition, most other groundwater sources adjacent to urban areas have been abandoned due to reduced water quality.  So our experience is that major development in a source protection zone can result in significant water quality deterioration in the aquifer requiring carbon intensive additional treatment and in some cases serious pollution that may render the source unusable resulting in alternative new water resources needing to be developed.

Wessex Water will also be assessing the impact on the water supply network.  Significant investment is likely to be required to serve the site, including new service reservoirs.

We will update stakeholders as results from our assessments become available.”