Water Resources East Anglia is identified as an area of serious water stress. We strongly recommend that you require any new residential developments (not only for this consultation) are constructed to meet the optional higher water efficiency standard of 110 litres/person/day, as per Requirement G2 in Part G of the Building Regulations 2010.
GNLP5005 & GNLP5023
Foul Drainage Capacity
There is limited capacity at Wymondham Water Recycling Centre. The development is however small, but we would recommend that the constraints analysis is updated from green to amber for utilities capacity for this site.
Flood Risk/Permitting
This allocation borders the River Bays which is designated as a main river. Please note that a Flood Risk Activity Permit will be required for any development within 8m of this river. There are also Environment Agency maintained assets bordering this river (high ground) and this will most likely be taken into account in any permit application. We would require a strip of land to be left close to the river to allow access and avoid compromising the defences.
Contamination
In relation to contamination, this site resides in Source Protection Zone 3 (further information on SPZs can be found here Groundwater source protection zones (SPZs) - GOV.UK (www.gov.uk)) and is also on a principal aquifer. The site also overlies a historic landfill (Stayground Lane).
This would therefore trigger a consultation with us at the planning application stage. We would expect to see contaminated land assessments submitted as part of the application.
We have provided 2 consultation responses to planning applications on this site (under reference AE/2004/014191/06 and AE/2021/126063/01). The latter was South Norfolk DC application which can be found on their website under reference 2021/0607. You will see a desk study has already been produced. We would recommend taking a look at the outputs of this alongside our 2021 response.
In terms of Environment Agency comments in relation to contaminated land, we provide comments when sites have a ‘previously contaminative use’ as defined by the DoE Industry Profiles. A full list can be found here DoE Industry Profiles (claire.co.uk). We consider Waste disposal/treatment sites to be High Polluting Potential Previous Uses. I note that the site is also on a historic landfill sites and the Wymondham site resides within source protection zone 3. We would therefore expect to see contaminated land risk assessments submitted should the sites be brought forward. We are pleased to see that this is referenced as part of the site assessments for these sites. Any application should provide proportionate but sufficient site investigation information (a risk assessment) prepared by a competent person to determine the existence or otherwise of contamination, its nature and extent, the risks it may pose and to whom/what (the ‘receptors’) so that these risks can be assessed and satisfactorily reduced to an acceptable level. The National Quality Mark Scheme (NQMS) accredits competent persons with regard to assessing and reporting land contamination issues.
As with nearly all sites affected by contamination, most land contamination issues are surmountable with sufficient assessment and/or remediation (and as such, costs) if required. On this basis we would not rule out any development categorically on land contamination grounds at this stage. Whether or not it is economically viable however would be based on any risk assessments and cost benefit determination by any such developer.
Our main interest is when there is the breaking of ground. If the application is for the siting of caravans on this land it is likely to be of less concern to us. We would likely request that there should not be any piling or if necessary that a piling risk assessment is undertaken as piling can mobilise contaminants. We are also sharing the below SuDS informative which contains some useful guidance for these sites.
Advice to LPA on Sustainable Drainage Systems (SuDS) informative
1. Infiltration sustainable drainage systems (SuDS) such as soakaways, unsealed porous pavement systems or infiltration basins shall only be used where it can be demonstrated that they will not pose a risk to the water environment.
2. Infiltration SuDS have the potential to provide mobilise pollutants and must not be constructed in contaminated ground. They would only be acceptable if a site investigation showed the presence of no significant contamination.
3. Only clean water from roofs can be directly discharged to any soakaway or watercourse. Systems for the discharge of surface water from associated hard-standing, roads and impermeable vehicle parking areas shall incorporate appropriate pollution prevention measures and a suitable number of SuDS treatment train components appropriate to the environmental sensitivity of the receiving waters.
4. The maximum acceptable depth for infiltration SuDS is 2.0 m below ground level, with a minimum of 1.2 m clearance between the base of infiltration SuDS and peak seasonal groundwater levels.
5. Deep bore and other deep soakaway systems are not appropriate in areas where groundwater constitutes a significant resource (that is where aquifer yield may support or already supports abstraction).
6. SuDS should be constructed in line with good practice and guidance documents which include the SuDS Manual (CIRIA C753, 2015), Guidance on the Construction of SuDS C768 and the Susdrain website. For further information on our requirements with regard to SuDS see our Groundwater protection position statements (2018), in particular Position Statements G1 and G9 – G13 available at: https://www.gov.uk/government/publications/groundwater-protection-position-statements
We recommend that developers should
1) Refer to our ‘Groundwater Protection’ website;
2) Refer to our CL:AIRE Water and Land Library (WALL) and the CLR11 risk management framework provided in https://www.gov.uk/guidance/land-contamination-how-to-manage-the-risks when dealing with land affected by contamination, and also includes the Guiding Principles for Land Contamination for the type of information that we require in order to assess risks to controlled waters from the site. The Local Authority can advise on risk to other receptors, for example human health;
3) Refer to our Land Contamination Technical Guidance;
4) Refer to ‘Position Statement on the Definition of Waste: Development Industry Code of Practice’;
5) Refer to British Standards BS 5930:1999 A2:2010 Code of practice for site investigations and BS10175:2011 A1: 2013 Investigation of potentially contaminated sites – code of practice
6) Refer to our ‘Piling and Penetrative Ground Improvement Methods on Land Affected by Contamination’ National Groundwater & Contaminated Land Centre Project NC/99/73. The selected method, including environmental mitigation measures, should be presented in a ‘Foundation Works Risk Assessment Report’, guidance on producing this can be found in Table 3 of ‘Piling Into Contaminated Sites’;
7) Refer to our ‘Good Practice for Decommissioning Boreholes and Wells’.
8) Refer to our ‘Dewatering building sites and other excavations: environmental permits’ guidance when temporary dewatering is proposed
Waste Management Licences
Waste Management Licence 70519 is located on site. We would expect this to be surrendered as appropriate should waste operations cease.
GNLP5014, GNLP5019, GNLP5020, GNLP5021 & GNLP5024
Foul Drainage
This site does not appear to have access to mains drainage. Therefore, private means of foul drainage may be necessary. We would therefore suggest that the constraints analysis for ‘utlilities infrastructure’ is updated from green to amber.
Government guidance contained within the National Planning Practice Guidance (Water supply, wastewater and water quality – considerations for planning applications, paragraph 020) sets out a hierarchy of drainage options that must be considered and discounted in the following order which must be followed at application stage:
1. Connection to the public sewer
2. Package sewage treatment plant (adopted in due course by the sewerage company or owned and operated under a new appointment or variation)
3. Septic Tank
Foul drainage should be connected to the main sewer. Where this is not possible, under the Environmental Permitting Regulations 2010 any discharge of sewage or trade effluent made to either surface water or groundwater will need to be registered as an exempt discharge activity or hold a permit issued by the Environment Agency, addition to planning permission. This applies to any discharge to inland freshwaters, coastal waters or relevant territorial waters.
Planning and permitting are separate regimes so we would highlight that should this site be brought forward that there is no guarantee of the granting of an Environmental Permit. We would therefore recommend applicants contact us as soon as possible regarding the application for the relevant permits. Upon receipt of a correctly filled in application form we will carry out an assessment.
Domestic effluent discharged from a treatment plant/septic tank at 2 cubic metres or less to ground or 5 cubic metres or less to surface water in any 24 hour period must comply with General Binding Rules provided that no public foul sewer is available to serve the development and that the site is not within a Groundwater Source Protection Zone.
A soakaway used to serve a non-mains drainage system must be sited no less than 10 metres from the nearest watercourse, not less than 10 metres from any other foul soakaway and not less than 50 metres from the nearest potable water supply, spring or borehole.
Where the proposed development involves the connection of foul drainage to an existing non-mains drainage system, the applicant should ensure that it is in a good state of repair, regularly de-sludged and of sufficient capacity to deal with any potential increase in flow and loading which may occur as a result of the development.
Where the existing non-mains drainage system is covered by a permit to discharge then an application to vary the permit will need to be made to reflect the increase in volume being discharged. It can take up to 13 weeks before we decide whether to vary a permit.
We trust this advice is useful.