The equivalent of 17 tanker loads of untreated sewage a day was illegally discharged into a Pembrokeshire river last year according to a local campaign group.

Research by The Cleddau Project (TCP) has revealed that around 55,814 cubic metres of raw sewage was discharged into special area of conservation on the Cleddau.

The discharge came from the Picton Playing Fields combined sewage overflow pipe (CSO), right next to Haverfordwest Skate Park.

The sewage should have been pumped up to Merlins Bridge sewage works for treatment, instead it was pouring directly into the Cleddau over a period of at least 18 months.

Volunteers from the Cleddau Project, a community-led organization focused on monitoring and restoring water quality, said that they had observed multiple instances of untreated sewage spilling into the Cleddau from the Picton Playing Fields overflow pipe, including large quantities of wet wipes, sanitary products and other materials, in breach of Welsh Water’s permit.

The volunteers had reported the pollution to Natural Resources Wales (NRW) on numerous occasions and became increasingly concerned about what they felt was a lack of action from the regulatory body.

Frustrated, they filed for environmental information requests with Welsh Water to obtain the pump performance data back to July 2022. Their analysis of this data showed a ‘catastrophic underperformance’ of the pumps at Picton Playing Fields over a period of at least 18 months.

During this time excess untreated sewage was pouring directly into the Cleddau.

The group says that despite a clear deviation from its NRW permit requirements, Welsh Water did not initiate corrective action until after a compliance visit from NRW in June 2023.

It then took nine months, until March this year, before the pumps were finally replaced and brought into compliance.

After the June 2023 visit, NRW assigned the incident a ‘minor’ grading. TCP is strongly challenging this, saying that the huge cumulative volume of untreated sewage discharging over at least 18 months into a highly sensitive, Special Area of Conservation (SAC) river points to systemic failure across both organisations.

The group says that, had Welsh Water and NRW acted sooner a lot of this pollution could have been avoided.

Natural Resources Wales said that Welsh Water ‘had to do better’ and that the Picton Playing Fields pumping station was also currently subject to a formal legal investigation for another matter.

Huwel Manley, Head of Operations for South West, NRW, said: “Dŵr Cymru Welsh Water (DCWW) has to do better when it comes to their performance against permitted flow conditions across Wales.

“In June 2023, NRW were made aware of issues at Picton Sewage Pumping Station in Haverfordwest. We were informed new pumps would be installed by 31 October 2023, and the water company was issued with a Compliance Assessment Report (CAR) reflecting this. “This work was not carried out by the deadline of 31 October 2023 and a further CAR was issued. This escalated the situation, indicating there was potential for significant risk to the environment and a formal warning was sent.

“The works to install new pumps was confirmed as completed in February 2024.”

The regulator said it was pushing for record levels of investment for the environment during the next investment period as well as strengthening and increasing its frontline capacity for water company regulation.

Welsh Water apologised for ‘falling short of expectations’ and said that it was working with TCP, a group that it helped fund.

A spokesperson for the company said: “We know our performance has fallen short of expectations on this occasion and for that we apologise.

“We have been working with the Cleddau Project, a citizen science group we help to fund, as well as share data and information with as part of our commitment to being transparent about our performance.”

Welsh Water said that a flow monitor had been installed at the Picton Fields pumping station several years before the NRW of 20205.

“This gave us insight into its performance earlier than our regulators required,” said the spokesperson.

“We were able to assess its flow, identifying the cause of the underperformance, which was the control of the pumps.”

He added that a bespoke control panel was needed to fix the problem, this had a 26-week manufacturing lead time due to its specialist nature. Work to install the new control panel started in December 2023, and it was operational in January.

“We expect the SPS to be compliant with its flow permit for 2024,” said the spokesperson.

He also pointed out that the majority of phosphate pollution on the Cleddau came from rural land use but that Welsh Water was committed to reducing its impact on the river.

The spokesperson added that Welsh Water was investing a total of of £9.4million at Letterston, Spittal and Rosemarket wastewater treatment works and planned to spend £100m to improve its assets and reduce impact on water quality between 2025 and 2030.

However, the Cleddau campaigners fear that this is too little too late.

“[The pollution is] likely to cause enormous harm to the aquatic ecosystems, public health and quality of Pembrokeshire’s iconic waterway,” said TCP.

"This investigation underscores an urgent need for systemic reform in NRW's regulatory framework. We’ve shown that by acting promptly on reports from the public, responding to sensor data and repairing broken equipment, much of this pollution could have been avoided. Yet WWDC and NRW have not implemented these basic safeguards. This is a relatively straightforward fix.

“The public deserves and expects the regulators and water companies to make a step change to sort this stuff out. The Cleddau is in dire straits. Things have got to change.”