Representation by Environment Agency (Environment Agency)
- Date submitted
- 23 June 2023
- Submitted by
- Other statutory consultees
Summary These Relevant Representations contain an overview of the project issues which fall within our remit. They are given without prejudice to any future detailed representations that we may make throughout the examination process. We may also have further representations to make when supplementary information becomes available in relation to the project. We have reviewed the draft Development Consent Order (DCO), Environmental Statement (ES) and supporting documents submitted to the Planning Inspectorate on the 27 February 2023 as part of the above application. We are pleased that some of the concerns and issues raised by the Environment Agency during pre-application consultation have been considered and addressed. However, there are aspects relating to the assessment and mitigation of groundwater impacts that will require further consideration and remain of particular concern to us. We would welcome the opportunity to make specific comments on the proposed drainage design during the Examination. The proposed drainage system poses risks to groundwater, surface water flooding, Water Framework Directive compliance. If these concerns are overcome, we consider it will be necessary to include a specific Requirement within the Development Consent Order (DCO) to ensure that the final agreed groundwater protection measures will be implemented. We can confirm at this stage that we consider that the ES provides a satisfactory assessment of the potential impacts of the scheme within our remit, except for the potential impacts to groundwater which we have raised with the applicant and in our comments below. Groundwater protection A potentially significant issue posed by the development is the plan to discharge treated liquid effluent to the ground. The development is located over the Chalk principal aquifer and is within the total catchment area (also referred to as source protection zone 3 (SPZ3)) for groundwater abstractions in the vicinity of the site. SPZ3 is defined as the area around an abstraction within which all groundwater ends up at an abstraction point. Several of the nearby abstractions are utilised for potable water supply including abstractions at East Hyde and Kings Walden. Groundwater will also provide baseflow to the Rivers Lee and Mimram located to the west and east of the site respectively. As such, the discharge of treated effluent from the proposed development could pollute the underlying groundwater, potentially impacting upon the viability of groundwater to be utilised as a resource in this area and pollute nearby rivers. The discharge will require an environmental permit and any permit granted will also include specific conditions that will need to be complied to for the lifetime of the discharge. At this time, we are not confident that a permit for the proposed discharge to ground could be granted. If the planned discharge cannot meet the requirements of an environmental permit, then a permit may not be issued. In its current form this proposal is reliant on the assumption that discharging treated effluent to ground will be acceptable, however we feel that our lack of confidence that a permit could be granted is a significant risk to the deliverability of the scheme in its current form. The discharge of treated effluent to ground should never be considered as a routine activity and should only be considered if no other options exist. The Environment Agency will only agree to developments involving release of sewage effluent, trade effluent or other contaminated discharges to ground if it is satisfied that it is not reasonable to make a connection to the public foul sewer. We are concerned that the applicant has not provided evidence to support that all other options have been explored and exhausted. We are also concerned that if a permit is granted but the discharge does not meet the stringent discharge quality criteria that will be required, given the sensitivity of the groundwater beneath the site, that the discharge to ground will have to be stopped and this could impact the operation of the airport. We also note that the current proposal utilises automated systems to divert potentially contaminated surface water flows for treatment prior to discharge to ground. We are concerned about the ability of these systems to detect relatively low concentrations of hazardous compounds, that are routinely utilised in airport operations, in surface water flows. This could potentially result in surface water contaminated with low concentrations of hazardous compounds not being treated and discharged to ground; this is not acceptable, and the Environment agency must take all necessary measures to prevent the input of hazardous substances to groundwater. Volume 5: Environmental Statement – Appendix 20.2: Water Framework Directive Compliance Assessment The Water Framework Directive (WFD) assessment has considered the implications of the main application site and off-site highway works, during both construction and operation, for the Lee (from Luton to Luton Hoo Lakes), Mimram (Whitwell to Codicote Bottom), Hiz (through Hitchin) and the Upper Lee Chalk groundwater body, with these water bodies screened in or out of the preliminary assessment depending on risks. The screening in/out of water bodies for the preliminary assessment didn’t raise any concerns. The preliminary assessment detailed that any risk of non-compliance with WFD was reduced to a “low adverse impact” (Table 7.2, page 31-32). As a result of the proposed drainage there is a potential risk of deterioration in groundwater quality, and therefore the risk of deterioration to the Upper Lee Chalk Water Framework Directive (WFD) designated groundwater body. The Upper Lee Chalk water body is classified as Poor for its Chemical (Groundwater) Status, due to a Poor Chemical Drinking Water Protected Area status and Poor General Chemical Test status. When an element is at its lowest status class (which is Poor for groundwater), no further deterioration of these elements is allowed. The proposals haven’t adequately demonstrated that there isn’t a risk of deterioration to the Upper Lee Chalk WFD designated water body, and therefore associated surface water features including the Lee (from Luton to Luton Hoo Lakes) and Mimram (Whitwell to Codicote bottom) water bodies. We would expect to see a detailed WFD assessment of the pollutant load, sensitivity, and quality of receiving water body and certainty of appropriate mitigation at the EIA. As this is expected at a detailed design stage, we would expect the WFD assessment to reflect the need for a more detailed assessment of this risk for both on-site and off-site highway interventions. Volume 5: Environmental Statement – Appendix 20.5: Water Cycle Strategy We are supportive of the inclusion of the Water Cycle Strategy, and value the intention to maintain potable water consumption at the 2019 baseline level. Failure to recognise and mitigate for the increased water consumption resulting from increased passenger numbers would have resulted in us making a representation toward this aspect of the proposal. This is linked with the Drainage Design Statement, and depending how this is resolved, the Water Cycle Strategy may require updating. Volume 5: Environmental Statement – Appendix 20.1 Flood Risk Assessment We agree that the sequential test has been applied correctly. The proposed development passes the sequential test for Fluvial flood risk but there are areas on site which are at medium or high surface water flood risk and therefore we are in agreement the exception test should be applied. The site is entirely within flood zone 1 including with the application of climate change. We have no concerns with regards to fluvial flood risk and agree the proposed works are highly unlikely to increase fluvial flood risk. However, there are areas of high surface water risk. We recommend that Luton Borough Council, in their role as lead local flood authority, are satisfied with the design of the surface water management scheme, although we retain an interest in the destination of the water, given our overview role in flood risk management. Volume 5: Environmental Statement – Chapter 17 and 19 The development will require permits and consents from the Environment Agency which will need to be considered in the design of the development submitted in the DCO application. The applicant has confirmed the intention to apply for a Deposit of waste for Recovery (DfR) permit and sought to secure agreement in principle from the Environment Agency before DCO submission to support the application. This has not occurred, and no submission has been made by the applicant, which does raise a risk to the delivery of the project. We are concerned that currently the management of waste and materials has been considered under the incorrect legislation. Rather than assessment in line with waste legislation, it has been considered in line with contaminated land legislation which has a lower bar for environmental protection; to seek betterment, rather than minimise impact. As such, the current proposals would pose an unacceptable risk to the environment and would be undeliverable, however we continue to work with the applicant to resolve these concerns. Disapplication of legislation – Article 43 The applicant is seeking to disapply the requirement to comply with any byelaws made under (or treated as though they are made under) paragraphs 5, 6 or 6A of the Water Resources Act 1991. We do not have any concerns to raise at this stage considering the current proposed development. Approvals are required under legislation which the applicant will apply for at the relevant stage of detailed design. We support that the applicant does not look to disapply the EPR flood risk activities permit requirements and as such will need to engage with us for a permit for the relevant works Requirements – Schedule 2 Paragraph 36 of Schedule 2 relates to discharge of the requirements. The draft states 10 business days, we wish to challenge that this should be 20 business days (15 business days, in addition to the 5 allocated to the LPA to issue the consultation) to better align with the Development Management Procedure Order 2015.