Cardross Scottish Water project leaves residents concerned

Argyll and Bute Council approved a Scottish Water plan last month for a 'combined sewer overflow' (CSO) chamber off Church Avenue in the village.

Some residents have objected to the disruption to the public park alongside Geilston Burn as well as the potential threat of pollution the watercourse.

Resident Sabina Astarita told the Advertiser said further discussions had taken place with Scottish Water and that a key problem was a pipe under the railway line needing enlarged.

She said: "Clearly, that would be a more expensive solution, but one that would actually solve this historic problem, which will only be exacerbated as the village continues to be developed.

"The burn is tidal. The water level varies significantly.

"The newly constructed bridge which traverses the burn has numerous water level markers. When the water level reaches the highest marker, the railway line at Bowling is flooded.

"So in addition to the proposed solution not addressing the root cause, the overflow may not flow, as desired by Scottish Water, into the sea.

"The CSO overflow occurs when capacity exceeds the main sewer capacity and also exceeds the CSO tank capacity."

Scottish Water says it has been engaging with the community since last August, and that it's considering the potential for further work in future to address carriageway flooding.

As well as the CSO chamber the utility company also wants to install associated pipework and manholes.

Graphic from Scottish Water explaining how CSO system works (Image: Scottish Water)

In February, the Scottish Environment Protection Agency told Cardross Community Council that the CSO was not their "preferred solution".

The watchdog said: "SEPA's preferred solution would have been for the removal of surface water from the combined sewer to reduce sewer flooding.

"However, this is not always technically feasible, and a new CSO can be authorised where it can be shown that water quality will not be adversely impacted.

"Scottish Water provided modelling data which indicated that the discharge would not adversely impact the water environment and therefore could be authorised."

NatureScot concluded the plans were "unlikely to have a significant effect" on the Geilston Burn or the adjacent Inner Clyde side of special scientific interest (SSSI).

A CSO effectively separates water and solids and is meant to prevent sewer contents from backing up into properties during heavy rainfall.

Scottish Water said 99 per cent of CSO discharge was excess rain or surface water and from sinks or showers. Less than 1 per cent is waste water from toilets.

The public park in Cardross where Scottish Water has permission to build a combined sewer outflow tank (Image: Google Street View)

They said the project in Cardross was to tackle flooding for about a dozen properties and the park's tennis courts and nearby roads.

The utility firm said they were considering a second phase to tackle carriageway flooding by tunnelling under the railway line.

A Scottish Water spokesperson said: “This is a significant investment of around £1.5million that will dramatically reduce the risk of sewer flooding for the community in Cardross.

“We will continue to do all that we can to mitigate any disruption while we deliver this vital project for the long-term benefit of the village.

"While we appreciate some people may be inconvenienced, we are committed to working with them, taking on board their concerns.

“Scottish Water is investing record levels, nearly a billion pounds a year, on improving its infrastructure to help meet increased demand and address the impact of climate change.

“We would like to thank all concerned for their patience and understanding.”