Affinity Water answers to EARA

  • Why are the EA and Affinity Water not objecting to the proposed quarry that runs a risk of contaminating the ground water source of public supplies in light of the recent media statements referred to above?


We lodged an objection in August 2018 on the basis that we were concerned that the proposed planning conditions did not provide sufficient, enforceable, protection for our abstractions for public water supply at Tyttenhanger and Roestock.  We were concerned that the combined effect of scavenge pumping at Hatfield and any pumping at the quarry could direct the bromate plume towards these boreholes.  We have reached an agreement with Brett Aggregates, that we can enforce, providing for strict controls and early warning mechanisms to ensure that there is no risk to our public water supply sources in the context of our Hatfield abstraction and its impact on the bromate plume.  We therefore withdrew our objection in May 2019.


  • We are requesting up to date readings showing the level of bromate contamination on all the boreholes on Ellenbrook Fields.​​ 


We will provide you with the readings that we have available as soon as we can.  A number of other organisations collect data with regards to bromate. SLR (consultants acting on behalf of Brett Aggregates) collect data in relation to the proposed quarry activity, whilst the Redland Minerals Limited and Crest Nicholson Limited collect data in the wider catchment. The Environment Agency also collect data in specific locations for different purposes.


  • Why are the EA not objecting to the quarry continuing whilst still unsure of what remediation works are needed to effectively remove the bromate plume and prevent further loss of source water supplies?​​ 


We ask you to refer this question to the EA.


  • What plans do you have to reassure us that our health has not been compromised, nor has there been an increase in mortality rates, caused by the contamination being in our water before closure of the Bishops Rise WPS in circa 2000 and what steps will be taken to monitor the situation regarding our health ongoing.​​ 


We monitor the quality of water leaving all our works and the quality of water at customers’ taps in accordance with the Water Supply (Water Quality) Regulations 2016.  We have not had any instances of water failing to meet the prescribed standard for bromate contained in these Regulations.


  • Who is accountable for the risks associated with the bromate plume including the risk to our water supply and the health risks to residents?​​ 


The Environment Agency is accountable for securing the remediation of the bromate plume by those responsible for the contamination, namely Crest Nicolson Limited and Redland Minerals Limited.  We are accountable for ensuring that all water we put into supply meets relevant drinking water quality standards.


Supplementary questions


  • Is Affinity Water objecting to the quarry now?


Following the further work undertaken by SLR (consultants acting on behalf of Brett Aggregates), the revised groundwater management plan submitted by Brett Aggregates which is enforceable by HCC and the undertaking provided by Brett Aggregates to us  we believe that the appropriate strict controls are in place to ensure no risk is present, so we have now removed our objection.


  • We have been told that the Bromate has already been detected on the quarry site; we have been refused / ignored regarding our request for data, the EA say they have not had this data and so cannot supply us. Does Affinity Water have the water bore hole data from the surrounding area and within the actual quarry, and what does that show?


As mentioned in point 2 above, there is some data collected from Affinity Water in relation to the bromate plume but not in the vicinity of the quarry. Our main purpose is to demonstrate that through our monitoring there is no bromate detected in the monitoring boreholes located south of the quarry and north of our Roestock and Tyttenhanger sources.  It needs to be noted, that other data is collected and disclosed to Affinity Water by third parties (as mentioned in point 2). This data is cross checked with our data where applicable to ensure consistency and confirm the plume location and bromate concentration. ​​ 


  • Can Affinity guarantee that any data is up to date and accurate?


Considering the amount of data collected by all interested parties and the monitoring frequency, we believe that adequate data is available for a robust risk assessment regarding the proposed quarrying activity.​​ 


  • Can you confirm that the quarry poses no risk whatsoever of drawing the Bromate plume South onto Ellenbrook Fields and affecting the source water?


Brett Aggregates’ operations may pose a risk if they are uncontrolled.  We believe that the proposed planning condition and the undertaking that Brett Aggregates has provided to us are sufficient to address any risk. ​​ 


  • If there is a risk of the bromate plume affecting the water source, what is the level of risk and how has this been calculated?


Please see comment above.


  • If there is a risk to the water source how does this sit with the recent media statements released by Marie Whaley (Affinity Water) and Sir James Bevan (Environment Agency) regarding the issue that within the next 5 years and beyond there will not enough water to meet demand?


We do not believe that there is a risk to public water supply now that we have secured an undertaking from Brett Aggregates.  Marie Whaley’s statement was a call to action asking for ALL stakeholders to take the issue of water conservation seriously. Climate change is predicted to reduce the amount of water we have available to supply while population growth results in a substantial increase in demand leading to an anticipated deficit of 256 Ml/day by 2080 if no action is taken.  Marie’s  statement was made as part​​ of our #WhyNotWater campaign calling for the government to introduce mandatory water labelling to help reduce per capita consumption of water.  ​​ 


  • If there is no risk to the water source from the bromate plume can you please explain how you have come to that conclusion?


As mentioned in previous comments above, we consider that the risk of the bromate plume migrating to other public water supply sources because of Brett’s proposed operations is being effectively managed through the very strict operating rules as set out both in the Groundwater Management Plan enforced by HCC and in the undertaking provided to us by  Brett Aggregates.​​ 


  • Is the water management plan guaranteed to be 100% successful? ​​ 


The heads of terms for the agreement between Affinity Water and Brett Aggregates provides for early warning triggers to be in place with data being available on telemetry for real time monitoring and risk assessment in the context of the dominant Hatfield abstraction. It provides for Brett Aggregates to cease pumping if there is a risk to public water supply.  As such, we are confident that this agreement is sufficient to effectively manage any risk arising from the proposed quarrying activity.


  • In the light of the failure in mitigating the plume at Bishops Rise pumping station – costing millions of pounds over 10 years - will Affinity Water cease operations and go for another remedial plan? ​​ 

The scavenging operation of Hatfield (Bishops Rise) has been partially successful, in terms of lowering the bromate concentrations detected at the downstream sources and has operated to protect public water supply.​​ 


As explained above, it is the responsibility of the Environment Agency to ensure that the persons responsible for the remediating the bromate plume, Crest Nicolson Limited and Redland Minerals Limited, take appropriate action.  There is a remediation notice in place that requires Crest Nicholson and Redland Minerals to meet the cost of scavenge pumping.   As you are aware, the current remediation notice expires this year and the EA carried out a public consultation on a replacement notice earlier this year to take all statements into account. Through this process, a long-term solution is being sought.



  • If another remedial plan is adopted by the Environmental Agency it is suggested by geologists that they should scavenge pump at hot spots on the plume. One of the highest readings is on Ellenbrook Fields, therefore if remedial action happens here it will be within 400 M from the quarry, so there will be a situation where one field is extracting bromate from the lower mineral horizon and the other (the quarry site) will be interfering with the same aquifer. Can you confirm that Affinity Water would not support the quarry plan in this situation?

If another site is selected in the vicinity of Brett’s quarry for scavenging operations similar to Hatfield, then the appropriate abstraction rate would need to be determined and the appropriate discharge route selected along with any associated treatment prior to discharge. At that time, any nearby abstraction (be it Brett’s or anyone else’s) will be taken into consideration with regards to any impacts on this new proposed scavenging scheme. It needs to be noted, that any scavenging operation in order to be successful would need​​ to operate at abstraction rates similar to Hatfield which can be an order of magnitude higher than those proposed by Brett’s abstraction for dewatering purposes.


  • NPPF policy is that no quarry activity takes place on contaminated land – what is Affinity Water’s position on this?

Affinity Water undertakes its own risk assessment in relation to operations in the chalk aquifer. In this instance, the contamination is already in the chalk aquifer below the proposed quarry, so the risk assessment is focused on any risks arising from changing the location or the concentration of bromate.



  • Can you explain that, given that the water companies since 2003 & EA have failed to treat this contamination, why an independent party is not being brought in to evaluate and suggest practical remedial action?


Crest Nicolson Limited and Redland Minerals Limited are responsible for taking action in respect of the bromate plume in accordance with the notice imposed by the Environment Agency.  We provide as much support as we can and participate on the Bromate Technical Working Group.  A lot of work has been done on bromate over the years by a number of organisations and the data has been shared amongst the parties to reach a common understanding of contaminant movement through the chalk aquifer. This was aided by the work done by two PhD studentships from UCL, as an independent body, in order to model the bromate plume and enhance our conceptual understanding.​​ 



  • Can you explain why there is not a review of any activity that may take place in the contaminated aquifer given that there is a potential threat to water supplies, not just locally but over a wide range of Hertfordshire?


As mentioned in earlier comments, separate risk assessments are undertaken for any activity near a groundwater source protection zone or in relation to the bromate plume to ensure adequate protection of the raw water quality of our sources. In collaboration with HCC and local authorities we frequently comment on and request specific actions to be taken to minimise any risk from the proposed activities.



  • Does Affinity Water and the applicants/agents have an agreement that should the water source become contaminated then Affinity Water will be compensated?

We have not sought an agreement for compensation because we are confident that the operating agreement puts in place robust arrangements for protection of our sources.  ​​