Consultee Comment

Application Number 22/503315/SUB

Case Officer: Terry Hardwick

CHSP Requirement 9 - Faversham Society Comments on Responses received from the Environment Agency and the Applicant dated 8^th August 2022

Author: Professor Sir David Melville CBE BSc PhD HonDSc CPhys FInstP

The EA and Applicant’s responses were made to the expert representation submitted on behalf of the Faversham Society detailing the adverse environmental impacts arising from the evidenced risk of the runoff and drainage arising from the large amounts of water which will be required to deal with a battery fire in the electrical compound. 

Environment Agency Response

We welcome the EA response, issued as a supplement to their earlier submission since it acknowledges that:

It has been brought to our attention that this condition may also cover the use of Fire Water, in the event of a fire from or around the batteries on site. Is this covered by any other conditions or, if not, could we please have all relevant documentation relating to Fire Water damage mitigation measures provided to us, so that we can update our response.

We believe that drainage approval is not currently covered by any other conditions and it is not possible to do so without publishing the size, design and chemistry of the BESS along with the Battery Safety Management Plan.

Applicant’s Response

The applicant in its response dated 22^nd June to queries raised by SBC  states:

“Any Requirements needing to be discharged prior to commencement of construction of these subsequent phases (e.g., Requirement 3, battery safety) will be the subject of separate future discharge applications.”

This stance is based on the flawed assumption that the changes needed to accommodate  potentially vast levels of fire run-off water are likely to involve minor revisions of the currently proposed drainage scheme. In particular: -

1          The proposed scheme is based on standard pluvial micro drainage calculations which will infiltrate through a permeable gravelled surface into a granular drainage blanket (for attenuation and filtration) where it will either soak into the ground below the electrical compound or be drained via a series of slotted pipe land drains.  These discharge into a sustainable urban drainage network of open unlined ditches to an outfall that flows into a designated protected area in the Thames Estuary.  The only contamination contemplated for positive management is the separation of hydrocarbons from vehicle petrochemical spills and oil from backup generators and transformers situated in a discrete hard surfaced bunded area.

2          This system, as designed, will be an ‘open door’ for the discharge of the large amounts of contaminated water that will be used by firefighters in the event of a battery fire into the ground beneath the electrical compound and the sustainable urban drainage network beyond.  Contaminated run-off water following a fire in the battery compound would, as a matter of fact, evidenced from previous incidents present a de facto major pollution incident.  In this context the proposed monitoring regime would be futile and could be viewed as closing the stable door after the horse has bolted.

3.         The toxic contaminants released from the drainage of run-off fire water would certainly result in catastrophic environmental damage to the ecosystems through leaching to the marshland, the foreshore, the marine environment and their associated ecology.  The immense ecological value of the Swale in particular is reflected in its designated status as a Site of Special Scientific Interest, a Special Protection Area, Marine Conservation Zone, and Ramsar site established under the terms of the Ramsar Convention of 1971 which the UK is bound by treaty to respect.  Leachate could result in serious environmental impacts as it can act as a transportation medium for hazardous substances. It may pollute soils or groundwater and transport contaminates over considerable distances, often many kilometres from the site, potentially contaminating groundwater and the receptor freshwater and marine environments.

4.         Fire run-off water leachates will inevitably carry various pollutants such as heavy metals, additives, electrolyte degradation products and dissolved gases. The latter, such as hydrogen fluoride, hydrochloric acid or sulphur dioxide (in the form of sulphuric acid) not only have a straightforward toxic effect but also alter the properties of receiving waters and solutions in soil. The acidification caused by these corrosive species may have the same effect as “acid rain”, lowering the pH and thus strongly impacting plants and animals.  They would also enhance the release of soil-bound heavy metals. Under more acidic conditions the actual toxicity of heavy metals is higher than it would be predicted from the metal concentration alone. There is direct evidence of the presence of toxic and dangerous contaminants in battery fire run-off water from recent research as well as the 2022 Merseyside Fire and Rescue report of analysis run-off water from the fire at the Carnegie Road Liverpool BESS.

A recent scientific publication by Held et al. (2022) in the journal Renewable and Sustainable Energy Reviews entitled “Thermal runaway and fire of electric vehicle lithium-ion battery and contamination of infrastructure facility” found that “the heavy metals nickel, cobalt and manganese were detected in very high acid-soluble concentrations [in the run-off water from a lithium-ion fire]. These levels exceed the limit for drinking water in Switzerland (where they are defined) by factors of 700 to 1,800. The limits for introducing fluids into the sewage system for industrial effluent in Switzerland are exceeded by factors of 20–70.”

In our earlier submission we presented evidence that approximately 1.25million gallons (5,683 m3) of water might be needed to suppress a single container fire and 175 million gallons (795,566 m3) if the whole 700MWh BESS is involved.

The applicants in their response suggest:

the drainage design incorporates a surface water pumping station and an outfall incorporating a non-return flap and a penstock valve which allows the electrical compound to be isolated from the wider drainage network, if necessary. The retained water can be tested and removed and treated offsite, if necessary.

As set out in the previous response, the electrical compound drainage design incorporates the ability to isolate the electrical compound from the wider drainage network, if necessary. consented Outline Battery Safety Plan is an“ One of the information requirements in the

Environmental Risk Assessment To ensure that the potential for indirect risks (e.g., through leakage or other emissions) is understood and (Best) Available Techniques (BAT) in relation to the” mitigated using methods consistent with Best specific battery chemistry selected.–   –

Requirements 2  detailed design, and 3 battery safety management of the DCO give the Council control and the ability to review the design of the Battery Energy Storage System

(BESS) and the mitigation measures incorporated into it’s design prior to it’s construction as phases 2 and 3 of the project.

Although difficult to decipher given the absence of any drainage layout plans it appears that the applicants are proposing to contain these huge amounts of fire run-off water within the electrical compound which contains all the electrical components including the high voltage 400kV grid connections. This is alarming and further demonstrates that the applicants have not appreciated the need to make separate provision for dealing with the effects of a potential BESS fire. Indeed where they do mention water storage in their response they say:

The drainage design submission has been designed to the 1:100-year return period plus 40% climate change and allows for approximately 4,765 m3 of water storage in the design.

As indicated in the figures above and our earlier submission this is insufficient to deal with the estimated run-off from a single container fire let alone fires involving multiple containers as seen elsewhere. The stark contrast between what is proposed and what might be needed  cannot be dealt with by their claim that in 12 months’ time:

The design of the BESS has not yet been finalised so any additional water storage requirement would be set out in response as part of the submission of detailed design information for the BESS ahead of its construction and the submission in respect of requirement 3 – Battery safety management, of the DCO.

‘Additional water storage’ cannot be taken to address the need to provide for the worst-case scenario of 167 times the run-off capacity compared to the current proposal of 4,765m3. To put this another way there is a need to ensure run-off provision equivalent to 318 olympic-sized swimming pools (of 2,500m3) or an area of 397,500 m2 (=98 acres). This is six times larger than the estimated size of the battery compound and will inevitably require a reassessment of the solar PV panel configuration.

In the absence of BESS details other than a proposed capacity of 700MWh this might be taken as a worst-case scenario requiring approximately 10% of the total CHSP site for run-off water storage in the event of a major fire incident.

It is inconceivable that this could be retro-fitted in phase 2 and 3 of the project when PV panel etc construction is already well underway.

Conclusion.

The proposed drainage network is not fit for purpose for the containment of these contaminants, nor is the proposed storage capacity remotely adequate to deal with the significant volumes of run-off water in the event of a BESS fire.  Requirement 9 should not be discharged until the applicants are able to show that they have taken a risk-based approach to the possibility of BESS fires with proposed works to safely isolate, contain, analyse and treat the likely large amounts of contaminated fire run-off water. Water used to contain a fire should not be allowed to escape either directly or via leaching under any circumstances.  This will require that details of BESS size, battery chemistry, container size/spacing and effective safety measures are known.

In the light of this, the application is premature. We strongly recommend that SBC defer any discharge of Requirement 9 pending the submission of the Battery Safety Management Plan which must address these absolutely fundamental health and safety issues.