Spotlight On: Housebuilding & Water Quality

Water management - H2O Building Services


As the UK population grows, estimated to increase by 6.6 million to 73.7 million over the next 15 years or so, new housing stock will be needed to ensure that new households have a roof over their heads.


However, it’s not just the growing population putting pressure on housing supply, with unsuitable accommodation also an increasingly urgent issue and affordability pressures meaning many are now unable to access the type of homes that meet their needs.


Recent research by the National Housing Federation and Crisis from Heriot-Watt University found that approximately 340,000 new homes will need to be built in England annually, with 145,000 of these to be affordable.


But despite the government’s goal of building 300,000 new homes each year, housing supply is falling behind, with around 233,000 new homes supplied in 2021/2022 and housebuilding lower now than it was at its peak in the 1960s.


One stumbling block for new developments is the amount of pollution that can be generated as a result of construction practices and the increased occupation of new homes, particularly where water quality is concerned.


How does construction affect water quality?


Construction sites can lead to water pollution incidents through the release of site waste such as building materials and litter, or as a result of fuel and chemical spills.


Fuel is often stored on site so that plant and machinery can be used, which increases the risk of accidental spillages. This can have a significant impact on waterways, killing plantlife fish and invertebrates, as well as affecting the potability of the water sources themselves if spillages take place close to abstraction points.


But it’s not just the construction itself that can have an impact on freshwater resources and new home occupation can also have a huge impact as well, with one of the biggest sources of nutrients in rivers, lakes and streams coming from discharged wastewater from both the local population and agriculture.


Back in 2019, Natural England advised local planning authorities not to approve plans and projects for new homes and new overnight accommodation in places where this was likely to increase nutrient emissions, as this could affect water quality and the condition of protected habitats.


Under current guidance from the organisation, new housing supply has been delayed in many regions because of the potential effects of nutrient emissions on protected habitats, with construction not able to go ahead unless nutrient neutrality assessments have been carried out and mitigation solutions implemented and operational.


What is nutrient neutrality?


Nutrient neutrality is a concept that developers may need to adopt in order to ensure that the level of nutrients like nitrates and phosphates in at-risk waterways and catchment areas does not increase as a result of the building work being done.


Nutrient pollution is one of the most pressing issues facing the nation’s freshwater habitats, with elevated levels reducing the capacity of the water to carry oxygen, accelerating the growth of certain plants (which can lead to damaging algal blooms) and disrupting the natural ecosystem, affecting biodiversity, plants and wildlife.


If housing developments need to be nutrient neutral, it will be necessary for nutrient discharge to be minimised to the extent that it is either equal to or lower than what was present at the site prior to the development.


Nutrient pollution is a relatively new problem for housebuilders, but one that affects both plan-making and decision-making. What makes it even more difficult to resolve is that different regions are affected in different ways, so there’s no one-size-fits-all solution to the problem.


Tackling water pollution AND supporting housebuilding


Towards the end of last month (May), the government announced a series of measures to improve water quality and tackle pollution at source while ensuring that thousands of homes can still be constructed, with a new list of more than 140 wastewater treatment works published that legally require to be upgraded in places affected by nutrient neutrality advice.


These upgrades will mean that aquatic ecosystems can be improved, while helping developers by reducing the mitigation requirements for new homes. Instead, water suppliers will need to meet strict nutrient removal standards in designated areas.


Chief of Natural England Marian Spain said: “Upgrading wastewater treatment works is an important step forward in reducing pollution in some of our most important protected areas for wildlife.


“Development and nature recovery should be delivered hand-in-hand, and so addressing the issue of pollution at source will ensure we can continue to build more sustainable homes for the future.”


In Poole Harbour, for example, following Natural England’s advice has had such a big impact that phosphorus levels will be reduced to those consistent with conservation objectives. The knock-on effect of this is that it will help restore this important habitat for bird species like black-tailed godwits, spoonbills and avocets.


What else can developers do?


Being proactive and prioritising water management across the board can help reduce the risks of pollution. This will involve carrying out a full ground investigation report so that you have all the necessary information to make the right decisions, covering the likes of historical land use, flood zones, water courses, groundwater, drainage, topography and conservation.


Also make sure that you’re fully abreast of all the latest regulations for water treatment and discharge so that you know you’re complying. Once you have this information, you can then carry out a full risk assessment that will inform your action plan for reducing water pollution risks.


It can also be useful to bring in consultants with in-depth expertise in these areas. If you’re keen to ensure that water quality isn’t compromised and that you’re not using more than you need to, get in touch with the H2o Building Services team today to see how we can help.