Agenda item

To invite Welsh Water to discuss water quality concerns and sewage concerns, particularly related to the Monmouth and Shirenewton area. 

Sharon Evans, Edward Bennett and Daniel Humphreys presented to the committee and answered the members’ questions.

Drinking Water Quality – Sharon Evans

• What happens to the lead pipes that are removed? How much do you predict remains in the system in the county? The lead pipe is replaced with a drinking water-approved plastic pipe (MDP) and then recycled. The 7,500 lead pipes mentioned are across Wales, not just Monmouthshire. Properties built before the 1970s likely have lead pipes. Welsh Water offers testing for lead in water upon request.
• Do you test groundwater in towns and villages? Welsh Water tests groundwater if it is used for drinking water supply. This testing is part of the 365-days-a-year regulatory monitoring.
• What procedure should a resident follow if they were to notice something unusual with their water? Residents should contact Welsh Water through their operational call centre, web chat, email, or Facebook. They can speak to a real person who will advise them on what to do based on their problem.
• What are the figures on Slide 5 e.g. 93.5m? Is water taken from Buckholt? The figure 93.5m refers to the elevation of the asset. The AOD figure refers to the pressure at each site. There are two water treatment works servicing the Monmouth area: Mayhill and Ffynon Gaer. Buckholt treatment works is not in regular use but is available as an emergency source.
• How many samplers go around houses and how are the areas chosen? There are 60 samplers who work across Wales. They are trained to take samples and can work in any area. The areas are chosen based on operational needs and events.
• When water is taken from Monmouth and goes down to Usk and Llangibby, how are the pipes cleaned, and how often? Pipes are flushed and cleaned regularly as part of operational maintenance. Specific projects like the Zonal Study Project focus on replacing old pipes.
• What is the effect of asbestos cement main pipes? Asbestos in the pipes is not harmful to health as it is only harmful when inhaled, not ingested. The pipes have a coating that prevents asbestos from getting into the water.
• How does upstream monitoring work and how often is there a concern? There are monitors for drinking water quality purposes along every river from which we extract, and there are monitors upstream of every extraction point. There is a process by which it is monitored 24/7, and if any problem is detected, the downstream extraction point will be shut down until the problem has passed. There has been no further event since the one in June 2021 in Monmouth, which was the only time in the last 15 years.
• What date was cryptosporidium was detected? Cryptosporidium is a potential risk in rural catchments and is managed daily. The specific date of detection was not provided.
• How easy is it for lead pipes to be changed to blue polyethylene for homeowners, and how does it get costed out? The cost of replacing lead pipes depends on whether the pipe is within the property boundary (homeowner's responsibility) or outside (water company's responsibility).
• Can you explain the term ‘Icing pipes’? This refers to a method used to cleanse the inside of a water main by pushing a slush of ice and salt (‘ice pigging’) through the pipe, removing any tuberculation.
• Despite DWI reporting high compliance levels, isolated incidents occur – are there any safeguards you can put in place or is it just a case of monitoring? Safeguards include upstream monitoring in the river to detect issues before they reach the abstraction point, allowing the abstraction to be shut down if necessary.
• Can you explain more about AMP8 and how it can help future upgrades to water quality? AMP 8 stands for Asset Management Plan 8, which is the business plan for investment in assets from 2025 to 2030. It aims to improve resilience and future-proof against risks.
• How can the problem of water pressure in Portskewett be addressed? – ACTION (to follow up with the capacity team to reply to Cllr Dymock)
• Regarding the isolated incident, were water samples taken and what did they show? If you don’t know the source how can you have a risk assessment to combat it in the next few years to ensure it doesn’t reoccur? We were unable to take samples from the river and look in the catchment for the source of the problem, but we know that the compound was a fatty acid used in foodstuffs. We were unable to pinpoint the source definitively, which is why there is now upstream monitoring in the river that would catch a similar problem in the future.
• How often is upstream monitoring done? Welsh Water does not monitor rivers and brooks on a day-to-day basis; this responsibility lies with Natural Resources Wales (NRW) and the Environment Agency. However, Welsh Water does conduct investigations to prioritise storm overflow assessments and understand the impact of their discharges on the environment.
• How much drinking water is currently leaking in the county and what are the main reasons? What is done to prevent it? Sharon did not have the information on leakage to hand and will follow up with the relevant team to provide an answer – ACTION (Sharon Evans to find out)

Sewer Capacity – Edward Bennett

• Should the main pipe at Shirenewton now be replaced, given that the problem of sewage emptying into the field, and the temporary solution of hay bales, has been going on for years? Repairs have been attempted in a phased approach, currently in Phase 5. Although that approach will continue, these comments will be fed back. Funding is available to try to reduce the frequency of storm overflows. Regarding hay bales and mitigations to safeguard areas, we will visit to check if they need to be replaced more frequently if they are fouling up and deteriorating.
• As the pipe can’t deal with extra sewage – e.g. Mounton House school can’t connect to it – is a moratorium on housebuilding not needed until the pipe is fully repaired? Because one of the main causes of the hydraulic issue in the network is down to our asset it is very difficult for us to say no to new houses at this point. This is why we go for ‘no detriment’, as we hold the line. We have to continue the approach of repairing what is ours to fix.
• The member from Shirenewton reiterated her concern about new housing, stating that ensuring ‘no detriment’ is not sufficient – the pipe should be fully repaired or replaced. She stated that the leaking pipe in Shirenewton means that there is a capacity problem, as defined by Planning Policy Wales Edition 12 6.6.9, which she quoted in full, and new building would therefore be contrary to it – ACTION: to provide a report for members and residents about concerns relating to Shirenewton ward
• Regarding housebuilding, how does Welsh Water assess capacity and infrastructure e.g. for the proposed 770 houses in Caldicot East? It’s about harm and detriment based on environmental and customer impact, which is how we would address it from a capacity standpoint. ‘No detriment’ means we don’t want to see a deterioration in any of those factors linked to planning. Further detail will be given in the next presentation.
• How does Welsh Water mitigate potential storm water overflow issues, given the additional permeable surfaces that will be created by these developments? A massive part of our focus in the next five-year period is to improve the reduction of spills causing harm to the environment and for us to become one of the leading companies in how we target our capital investment to add the most value to the environment, rather than just having spill reduction. These new developments will need to go through a process that isn’t coordinated through Welsh Water, in which they would need to ensure that all of the water generated at that site has been considered. The release of the water is generally held back to whatever the rate of the greenfield site is, so if there is building on a large area there would need to be enough attenuation to only allow the greenfield site volume off into the environment.
• Do you work together with Natural Resources Wales, particularly in regard to flooding? Yes, we liaise with NRW on a number of elements, including resilience in our communities, linked to flooding, whether sewage, fluvial, coastal defence, etc. We will liaise with regulators based on where they feel our storm overflows are causing most harm to the environment: they will agree a list with us on how we deal with them.
• Does consideration of surface water include the existing risk i.e. the large proportion of green fields that flood at this site? No surface water is allowed into the public sewer system for these new developments. There has to be significant justification to do that, which will have to be agreed. So if that site is affected by fluvial flooding, the developer will need to take it into consideration during their planning.
• Is it usual to expect bales of hay to mitigate the problem of sewage overflow? Using bales of hay around manhole chambers is not a common practice and is only done out of necessity. It is not a long-term solution, and Welsh Water aims to stop such discharges. We don’t have the same problem in other areas.
• How often does the hay bales measure happen and what is done? How often do you expect it to go on for and what is there to prevent flooding removing the hay bales? Welsh Water checks the bales of hay approximately every six months. The bales are intended purely to slow the velocity so the land isn’t scoured. When flooding occurs, we remove any offending materials and assess damage to the land, coordinating with the landowner for cleanup and containment.
• How is the potential spread of disease mitigated? This is why the heras fencing is in place to keep people away. The bales are around the chamber itself and the fencing is slightly further away. In this instance there is some leeching into the river and stream because the manhole chambers adjoin part of the chamber, which is why we’re in regular communication with NRW about what we’re doing.
• Vegetation by the brook that has grown from being fertilised shows that the containment isn’t working. Should Welsh Water standards not be higher than having a sewage system described as ‘adequate’ when relying on bales of hay? The use of bales of hay is not considered an adequate or long-term solution. It is a temporary measure to slow down the velocity of sewage. Welsh Water acknowledges that this is not desirable and is working on more permanent solutions.
• There is a problem in Monmouth of drains backing up. Who pays for HMAs (Hydraulic Model Assessment) for new planning areas? Developers are asked to provide us with HMAs to show the level of detriment that their proposed development could have on the public sewer system, taking into consideration how the potable water supply might be affected and the treatment works capacity. When there is a problem affecting a catchment we will be aware of it and have a hydraulic model for that catchment which is a detailed model telling us what is happening at various points in the area, used to form part of the HMA that the developer will invest in. The hydraulic models in place will determine whether an HMA is required, or an offsetting scheme as part of the development.
• Is there any information about the leakage into the river from Priory Street in Monmouth? We are aware of this and spoke today to MCC about how to approach the problem. We have progressed investigations and know it isn’t linked to a public sewer, and are working with the council on how best to gain a full understanding of the source of the problem and then to resolve it. A resolution won’t be possible until we have first understood exactly which properties are affected. A number of odour complaints have been generated and complaints made about a footpath so we have first concentrated on containment and intercepting the flow into the public sewer.

River Water Quality – Daniel Humphreys

• What does discharge during storms look like e.g. filtering out litter? How often do you experience discharge outside storm events e.g. when it rains heavily? Most assets have screens to filter out litter and debris. Discharges typically occur during heavy rainfall or storm events.
• Are you doing anything to address PFAs (perfluoroalkoxy alkane)? Welsh Water tests for PFAS and other chemicals through a rolling programme and works with traders to monitor discharges into the sewer system.
• Are water treatment works in Monmouth close to completion? The ongoing work at Monmouth is expected to be completed by March 2025.
• Are you lobbying about urban creep? Welsh Water is in dialogue with Welsh Government to address urban creep and its effect on the sewer system.
• Is information about sewage overflow easily available publicly? Are there set levels over which it shouldn’t go? Storm overflow information is available on Welsh Water’s website. The best way to find information would be to use the search tool in the top right corner. Information is also there about the annual spills from each asset (type ‘EDM’ into the search bar), going back to 2021.
• How is the sewage impact on rivers and brooks monitored? Welsh Water does not conduct day-to-day river monitoring; this is the responsibility of Natural Resources Wales (NRW) and the Environment Agency (EA). Welsh Water does conduct investigations to prioritise storm overflow assessments and understand their impact on the environment.
• What monitoring is there about the effect of runoff of manure from poultry farms? Welsh Water is aware of the effect of poultry farms on phosphorus levels in rivers. They support initiatives like citizen science projects and work with stakeholders to address these issues. However, the regulation of agricultural pollution, including phosphorus, is managed by NRW and EA.
• In terms of standards, are licences and permits involved? Yes, there is a permit in place for the majority of our assets, with a programme in place to get the remainder permitted, for which a timeline is agreed with the regulator. The permits have a standard text of conditions that we have to meet, with each storm overflow designed to that particular permit. Similarly, set values are given at Waste Water treatment works e.g. 20mg per litre of a particular nutrient need to be reached. We will then continue to report on this figure through monitoring and samplers – the samplers work independently and report directly to the regulator.
• Do the permits regulate the volume of sewage that can be discharged in storm overflow situations? We are looking now to ensure that we are reaching the maximum amount of flow, and are in discussions with NRW. The majority of our overflows are a pipe; once the maximum capacity of that pipe is reached the chamber will lift and it will discharge. So there is an engineering element – treatment works used to be built to three times the dry weather flow. There might be a volume limit on some assets but not on others.
• What about phosphates in Abergavenny? Welsh Water is aware of the impact of phosphates from agricultural runoff, including poultry farms. They have been working on reducing phosphorus levels in rivers through various initiatives, including the review of permits process and investment in treatment works to improve phosphorus removal. However, the regulation of agricultural pollution, including phosphorus, is managed by NRW and the EA.
• When consulted on planning are you able to make stipulations on things like driveways? In terms of permeable areas there is nothing legally that Welsh Water can do nor, presumably, the council, as planning permission isn’t required for a paved driveway, for example.
• Is there a possibility of bills being doubled before Christmas? Bills are decided by Ofwat, rather than Welsh Water. They are a stringent regulator and try to look after the customer. We use the not-for-profit model and have added tariffs for customers, given that many are struggling financially, including those who work full-time. Residents should reach out to Welsh Water if they have concerns.
• What happens to the sludge and debris that get removed? We will now be taking more sludge away from the treatment works. In Monmouthshire, we dry out the sludge as much as possible first then take it down to Cardiff Waste Water treatment works, where there is an advanced digestion process, in which it is burned and the resultant gases are returned to power parts of the plant and excess energy returned to the national grid. At the other end it comes out as ‘cake’ used as free manure for farmland in the local area following nutrient sampling at those locations to ensure they are suitable to receive it.
• NRW frequently cuts trees back from riverbanks, which could increase river temperature – will they not do so in the future? The cutting back of trees on riverbanks by NRW is likely done to prevent flooding and blockages. However, increasing tree cover along riverbanks can help to maintain cooler river temperatures, which is beneficial for preventing algal blooms. This is a balance that NRW would need to manage, considering both flood prevention and river health.
• How does phosphorus removal from drinking water at Monmouth work? The treatment works at Pontrilas, Ross, and Monmouth are involved in phosphorus removal processes. The water abstracted for drinking purposes in Monmouth has already gone through these treatment works, which include phosphorus stripping to reduce the levels of phosphorus in the water. The treatment works along the Wye Valley, including those at Pontrilas and Ross, are designed to reduce phosphorus levels before the water reaches the Monmouth area. This helps to mitigate the impact on the River Monnow and the River Lugg, which are known to be affected by high phosphorus levels.
• How does phosphorus not affect drinking water? Phosphorus is present in drinking water, but the levels are very low and are not harmful to human health. The drinking water is treated to ensure it meets safety standards, and the phosphorus levels are kept within safe limits.
• Can you explain what ‘Requirement of HMA or surface water removal agreements’ means on the Pwllmeryic slide (p15)? Because we understand that there are impacts on that network of the public sewer, we are asking that we do not have a detriment as a result of the proposed development. There is either a HMA that defines the detriment and proposes mitigations, or there is offsetting: if we know what the dry weather flows intend to be, we will need to see that removed in storm response from the catchment.
• Does Welsh Water or the developer do the HMA? Is it to do with hydraulic capacity rather than whether the pipe is in a repaired state or not? The HMA is undertaken by the developer, using qualified consultants, and shared with us. What we are doing is offsetting existing surface water that connects into the public sewer. The detriment is linked to the manholes discharging and prolonged spills from storm overflows: we need to fix the lengths of sewer that are allowing that ingress into the network.
• How would a developer mitigate surface water going into the sewage system? They would help us to look for sources of water that could be removed e.g. highway drainage, land drains, etc.

Chair’s Summary:

Councillor Thomas asked about phosphates in rivers, particularly in Abergavenny, and the impact of manure from chicken farms. Councillor Brown raised concerns about the adequacy of the sewerage system, particularly in relation to the use of bales of hay to stop sewage leakage and the need for proper repair before additional housing. Councillor Strong questioned the use of bales of hay to stop sewage leakage and how many other places in Monmouthshire are using this method. Councillor Dymock enquired about low water pressure in her area and how Welsh Water ensures increased demands are met, including stormwater assessments. Councillor Brown expressed concerns about lead pipes, leakages in Monmouthshire, and the use of bales of hay. The Chair raised questions about water drainage in Monmouth, the need for hydraulic model assessments (HMAs) for new planning areas, and the issue of sewage leakage into the river on Priory Street.