The Veterinary Medicines Directorate (VMD) has evaluated the report and while acknowledging the general findings, also recognises that no definitive conclusions can be drawn from it. The VMD works closely with the Environment Agency and was already aware of the monitoring data, which are pivotal to the publication.

The publication suggests that veterinary medicines may be contributing to the levels of parasiticides present in the UK waters. The paper under discussion only loosely acknowledges that there is a lack of understanding and data in key areas to ascertain if veterinary medicines are causing harm in the environment. Such areas include the need to assess how much of these compounds are bound and not in free form, and therefore unavailable to cause harm. These aspects need to be considered when evaluating the potential impact of these compounds on the aquatic environment and are not emphasised in the report. Importantly, the report also did not distinguish exposure routes of other potential sources of parasiticide (e.g. ant baits, use in greenhouses, historic agricultural use and products used to protect textiles), which may be significant. Much uncertainty remains, therefore, over the actual contribution from veterinary medicinal use.

Parasiticides are used in veterinary medicines for the treatment of fleas and ticks on companion animals. It is possible that following their use on dogs and cats, some parasiticides may reach the aquatic environment. The environmental exposure assessments conducted for such flea products, however, consider the exposure of the aquatic environment to be low.

Medicines containing imidacloprid and fipronil are accompanied by advice to users to keep treated animals out of watercourses for 2 to 4 days after treatment. If these measures are followed, it is expected that exposure to the environment should be negligible.

Due to concerns and uncertainties raised by previous research and monitoring data, the VMD commissioned research in 2019 to investigate the potential environmental exposure pathways for dog and cat flea and tick products, to assess the significance of the use of neonicotinoids (e.g. imidacloprid) and other parasiticides (e.g. fipronil) on the aquatic environment. This research is due to be completed in March 2023.

Pending the findings of this commissioned research, and other available evidence, currently we do not have any plans to change the existing regulatory controls on veterinary medicines, including the use of flea treatments for pets and the existing risk mitigation warnings, which protect animal health, human health and the environment.

Defra is committed to continuing to consider the evidence to inform any policy decisions or other interventions such as reinforcing the message not to wash animals for the period stipulated.

Medicines containing imidacloprid and fipronil are accompanied by advice to users to keep treated animals out of watercourses for 2 to 4 days after treatment. If these measures are followed, it is expected that exposure to the environment should be negligible.

Due to concerns and uncertainties raised by previous research and monitoring data, the Veterinary Medicines Directorate (VMD) commissioned research in 2019 to investigate the potential environmental exposure pathways for dog and cat flea and tick products, to assess the significance of the use of neonicotinoids (e.g. imidacloprid) and other parasiticides (e.g. fipronil) on the aquatic environment. This research is ongoing. In addition, the relevance of other sources and exposure routes of these parasiticides, which could be significant, is yet to be elucidated.

Pending the findings from this commissioned research, and other available evidence, currently we do not have any plans to change the existing regulatory controls on veterinary medicines, including the use of flea treatments for pets and the existing risk mitigation warnings, which protect animal health, human health and the environment.

The VMD is committed to continuing to consider the evidence to inform any policy decisions or other interventions such as reinforcing the message not to wash animals for the period stipulated.

The Environment Agency (EA) risk-manages the spread of contaminants into the mid-Chiltern groundwater body using the CLR11/Land Contamination Risk Management framework, and the EA’s approach to groundwater protection. The EA agree voluntary remediation statements with relevant parties, and/or serve mandatory remediation notices under Part 2A of the Environmental Protection Act 1990 (EPA).

The EPA also gives the EA the power to enforce and control emissions to groundwater which is part of the Water Framework Directive’s Thames River Basin Management Plan. The plan provides a detailed explanation of the management of both waste water, and pollution from towns, cities and transport. Measures include, but are not limited to:

• The EA issues environmental permits to protect the environment from pollutants.

• They work with the water industry to develop a long-term strategy for sewerage to prevent deterioration of permitted discharges.

• The EA and the Health and Safety Inspectorate enforce restrictions and bans on the use of certain chemicals.

• Local Government considers the impact on water quality in all aspects of planning and development.

• The EA uses anti-pollution works powers under the Water Resources Act 1991 to prevent or clean up small scale pollution, e.g. repairing misconnections.

• Industry, manufacturing and other business comply with existing regulations, e.g. Environmental Permitting (England and Wales) Regulations 2010 to make sure that chemicals are properly managed and surface water drainage is properly used and maintained.

• The EA and Highways England apply the memorandum of understanding agreement covering the strategic road network and remediation of high risk outfalls.

• The EA and Network Rail operate under the terms of a memorandum of understanding covering contaminated land, water discharge and use of pesticides.

• The EA and the water industry investigate and deal with misconnections, for example, through the National Misconnections Strategy group and in accordance with Defra’s diffuse urban action plan.

• Local Government works with industry, manufacturing and other business (Local Enterprise Partnerships), and non-governmental organisations (catchment partnerships and Local Nature Partnerships) to develop joint improvement programmes.

The site adjacent to Newyears Green Bourne (between Harvil Road and Harefield No.2 Lake) where High Speed 2 (HS2) is to be constructed is not designated as ‘Contaminated Land’ under the Environmental Protection Act 1991 (EPA). However, the Newyears Green Lane landfill site, located 400 metres to the North East of the site adjacent to Newyears Green Bourne is ‘Contaminated Land’.

HS2 have reviewed the potential for contamination to be present on the site adjacent to Newyears Green Bourne by referring to historic mapping, a site walkover and the sampling of groundwater. This investigation has not highlighted any previous activities likely to have caused contamination of the ground or the presence of any contamination attributable to activities on the site.

HS2 contractors are currently assessing risks associated with test piling at this site as part of an application for approval under Schedule 33 of the High Speed Rail (London – West Midlands) Act 2017. The Environment Agency will then review their risk assessment, which includes consideration of impacts on public water supply abstraction at Blackford pumping station.

On 26 May 2011, in accordance with Part 2A of the Environmental Protection Act 1990, the London Borough of Hillingdon determined the land at the former ‘New Years Green Lane Landfill Site’ as Contaminated Land as defined by Section 78A (2) of the Environmental Protection Act 1990 (the Act).

On 6 July 2011, the Environment Agency (EA) agreed to designate the land at New Years Green Landfill as a Special Site pursuant to Section 78C (6) (b) of the Act. The site is now within the regulatory control of the EA under Part IIA of the Act.

There is no proposal to undertake any such drilling activity at the landfill site. However, the EA is involved in the technical review of any drilling proposals at this landfill. As a minimum requirement, any drilling works in the landfill or in areas where waste is suspected must utilise “clean” drilling methodologies to avoid potential cross contamination between different parts of the geology.

The Environment Agency (EA) requires well pads to be constructed so that water run-off is captured on the site and does not cause pollution. The environmental permits also require operators to carry out regular monitoring of nearby surface water locations as part of agreed Emissions Monitoring Plans.

The EA carries out regular inspections, audits and unannounced spot checks to ensure operators are compliant with its environmental obligations. During site inspections officers will check for leaks or spillages on the well pad surface. EA staff also carry out visual inspections off site.

Brofiscin quarry is on an aquifer (water bearing strata/rock), which is hydrogeologically disconnected from the aquifer beneath Elan Valley reservoirs and the associated aqueduct that contribute to Birmingham public water supply. The distance that separates the two locations is significant; therefore there is no pathway for contamination to migrate from the quarry to the Elan aquifer. The Elan aquifer is the nearest aquifer to Brofiscin quarry that contributes to Birmingham’s public water supply and the Environment Agency does not consider Brofiscin quarry to present any risk to Birmingham’s water supply.

Natural Resources Wales is responsible for regulating the Brofiscin quarry site. Any risks relating to this site are a matter for the devolved Welsh Government.

Brofiscin quarry is on an aquifer (water bearing strata/rock), which is hydrogeologically disconnected from the aquifer beneath Elan Valley reservoirs and the associated aqueduct that contribute to Birmingham public water supply. The distance that separates the two locations is significant; therefore there is no pathway for contamination to migrate from the quarry to the Elan aquifer. The Elan aquifer is the nearest aquifer to Brofiscin quarry that contributes to Birmingham’s public water supply and the Environment Agency does not consider Brofiscin quarry to present any risk to Birmingham’s water supply.

Natural Resources Wales is responsible for regulating the Brofiscin quarry site. Any risks relating to this site are a matter for the devolved Welsh Government.

The class of substances known as Endocrine disruptors (EDCs) which include oestrogens found in contraceptive pills are a hazard to some wildlife. While it is correct that EDCs are a recognised environmental issue, which continues to be researched with a view to the protection of wildlife, EDCs do not pose a threat to drinking water supplies as drinking water treatment facilities will remove oestrogens, if they were to occur in river water.

The Environment Agency is currently commissioning work to survey the incidence and severity of intersex in wild fish in a number of rivers that were surveyed 15 years ago, to assess how the situation may have changed.

The Government is aware that a high level of erucic acid has been detected in some oilseed rape deliveries to crushing plants over the past year. The Government is working with the industry to understand the cause of the problem. A survey is being carried out by the supply chain to capture data on the seed used as well as the crop production, harvest and storage methods. This information will be independently analysed by the Agriculture and Horticulture Development Board.

Maximum permitted levels for erucic acid in products entering the food chain are set under EU Commission Regulation No 1881/2006 (as amended) setting maximum levels for certain contaminants in foodstuffs. Local authority enforcement officers undertake routine monitoring to check compliance with the legislation.