Study identifies risks to drinking water from UKOG’s South Downs oil drilling plan


The Markwells Wood oil site

New questions have been raised about whether drilling for oil should be allowed in an area of the South Downs that feeds a source of drinking water.

UK Oil and Gas Investments plc (UKOG) has applied for permission to drill new wells and produce oil at Markwells Wood. The site is in the catchment of the Bedhampton & Havant Springs, which provide water to the Portsmouth area.

An independent study for a local community group has concluded that water contaminated by oil exploration or production at Markwells Wood could quickly reach the springs 8km away.

It also argues that the area had been incorrectly classified for groundwater protection and should have greater safeguards that would prohibit drilling for oil.

Markwells Wood Watch, which commissioned the study, has urged the South Downs National Park Authority to refuse planning permission.

In November last year, both the Environment Agency and Portsmouth Water objected to UKOG’s planning application for Markwell’s Wood. They said the company’s groundwater risk assessment was inadequate. The two organisations are expected to comment next week on a revised risk assessment.

Speed of water

The threat to drinking water depends partly on the speed with which any contaminated water could travel underground through the chalk to the Bedhampton & Havant Springs.

Aidan Foley, the author of The Markwells Wood Watch study, estimated that groundwater in the chalk aquifer at Markwells Wood could reach the springs in around 10 days. This is far faster than the Environment Agency (EA) has estimated.

The EA has said it would oppose hydrocarbon development in areas where underground water below a drill site could reach a drinking water source in no more than 50 days. These areas are classified as a Source Protection Zone 1 or SPZ1.

Markwells Wood is classified as a Source Protection Zone 2 (SPZ2), an area within 51-400 days travel time to a water source.

But Dr Foley said:

“There is considerable justification for the designation of the area around the UKOG site as within SPZ1.”

Markwells Wood Watch SPZ1 campaign

Markwells Wood Watch SPZ1 campaign. Photo: Markwells Wood Watch

Fissures in the chalk

One way groundwater and pollutants can travel rapidly through chalk is along what are known as karstic features. This is where chalk is dissolved to create fissures and conduits, along which water and contaminants can flow.

Last year, the Environment Agency said if there was strong evidence to suggest karstic flows in the area of the UKOG site it would treat it as if it was in an SPZ1 and oppose oil and gas operations.


UKOG’s revised risk assessment concluded that the chalk near Markwells Wood had “less potential for solution weathering and karstic flows” than other areas in the South Downs.

But Dr Foley concluded that sink holes and dry valleys around UKOG’s proposed site and along the route for vehicles visiting the site were evidence of underground fissures in the chalk.

Dr Foley said:

“All of the geological and groundwater conditions required for karstification of the Chalk Principal Aquifer are in place at Markwells Wood.

“There is an almost complete absence of surface water within the district, with the exception of ‘Winterbournes’ flowing in normally dry valleys during periods of unusually high groundwater recharge, thus indicating that all flow is concentrated in the subsurface”.

Dr Foley said:

“Due to the high groundwater velocities (up to several kilometres per day) that frequently occur within flowing fractures, fissures and conduits, karstic groundwater supplies are among those most vulnerable to pollution.”

He said tracer tests from nearby Rowlands Castle proved that groundwater was travelling more than 12km a day and reaching the springs at Havant in about nine hours.

He said:

“The weight of these observations, on the basis of multiple lines of evidence, suggest that karstic groundwater flow conditions, of potentially kilometres per hour, are present in the vicinity of the UKOG site at Markwells Wood.

“There is little evidence to suggest that what takes 9 hours to travel from Rowlands Castle to Havant (a distance of 4.6 km), would take over 50 days to travel from the UKOG site to Rowlands Castle (a distance of less than 3.5 km).”

He said the delineation of the SPZ1 and SPZ2 zones appeared to be based on what he called “incomplete mapping of surface karst features”. He also questioned the basis of the calculations of the transport of contaminants.



Jo Hawes, who lives in Forestside, the nearest village to the Markwells Wood, said:

“The risk of water pollution as a result of drilling for oil is obvious. I believe the local authorities must take a precautionary stance and not allow an oil company to chase short term profits at the expense of our long term health.”

Reed Paget, a member of Markwells Wood Watch, said:

“It is now clear that the groundwater in this region is moving very quickly and if there is an oil spill, the people of Portsmouth could have chemicals in their drinking water in a matter of days. This is far too great a risk to accept. I hope Portsmouth Water and the EA do what’s right for the local population and object to UKOG’s oil extraction proposal next week”.

UKOG response

UKOG gave the following response:

“The report commissioned by MW Watch has been written in response to the old groundwater risk assessment submitted with our planning application in September 2016. However, subsequent to this and following discussions with the Environment Agency and Portsmouth Water, we have carried out a more comprehensive and detailed assessment. This was delivered to the South Downs National Park Authority in early March of this year and is currently being reviewed by both the Environment Agency and Portsmouth Water as part of the statutory planning application consultation process.

“Our assessment, like the report commissioned by MW Watch, recognises the high sensitivity of the chalk aquifer and shows that robust mitigation measures are required to manage the risks associated with our development. Since the wellsite has already been constructed in accordance with modern industry standards, the only potential risk associated with our development relates to the construction of new oil wells through the chalk aquifer.

“This low risk will be managed by constructing new wells using the same techniques used in the water well drilling industry. This will include using a British manufactured, natural, biodegradable drilling fluid in our operations. This zero-hazard water-based drilling fluid is the only drilling fluid to be formally approved by the Department for the Environment, Food and Rural Affairs for use in drilling wells for public water supply and will help to ensure that there is no impact to the Havant & Bedhampton Springs during the drilling process.”

The South Downs National Park Authority is expected to consider the UKOG application on 11 May 2017.


UKOG submits new information on South Downs oil drilling

DrillOrDrop page on Markwells Wood

Planning application documents

Dr Foley’s report for Markwells Wood Watch

Updated 4 April 2017 to include response from UK Oil & Gas

40 replies »

  1. Full credit to Markwells Wood Watch for commissioning this study. This industry is not to be trusted. Full scrutiny of all the industries reports is needed to obtain the full facts. Only then can informed decisions be made by planning authorities.

  2. If, but and very small maybes! You may get hit by a car crossing the road. You may get struck by lighting in a storm. Risk no bigger than my examples . . Just scaremongering delay tactics!

  3. I don’t think this an April fools joke at all, is interesting, that the recent increase in sinkholes across the world may have an effect on any oil and gas exploration.
    We mistakenly believe we live on a stable hard crust of rock above a semi molten mantle. The truth seems to be that the crust is far from stable, as many civilisations have found to their cost in the past.
    This is a video showing some of the filmed events, there are many more.

    I like the electromagnetic solar minimum/maximum explanation.
    Perhaps we should be more careful where we drill? But I doubt the oil and gas industry will take any notice?

  4. Can you provide a list of sinkhole occurrences in the UK and their proximity to oil and gas production.? I’d been really interested to see the comprehensive list. Or are you making it up? Remember it’s not April fools day anymore.

    • I didn’t mention the oil and gas industry, nor does the video propose that. Did you see it all the way through? I doubt it considering you are missing it entirely? There are many possible explanations for these increasing numbers of sinkholes and in UK too, pipes broken, underground water courses, building on unstable surfaces, increased run off from newly hard paved areas, the electromagnetic cause proposed by this video, probably a bunch of other stuff we have no concept of too.
      What is interesting is that this phenomenon is on the increase, if you wanted to link that to the oil and gas industry, then you only need to look at the Texas in the US and also Canada, Russia and China, however the possible point of all this is that the earth’s crust is not a stable structure and the parameters that we thought were appropriate and safe for drilling, may not be appropriate or safe at all. The issue of cavitation due to high pressure water and fluid injection and fracking and extraction is never addressed, look at the Oroville dam spillway which was not equipped with cavitation protection measures, fast flowing water and trapped air are a powerfully destructive force if left unaddressed, The possible creation of new earthquakes by destabilising sub strata and causing release of, or increased pressure on previously stable strata are rarely if ever addressed, nor is the long term effects of regular increasing and repetitive fracking producing explosions and damage to sub strata stability, particularly in UK where the population density and depletion of aquifers, increased run off from building on agricultural ground and paving over aquifer collection zones, badly installed and maintained pipework,both foul and surface water, gas leaking into underground cavities, we see a number of explosions in UK and across the world just from leaking gas pipes, one very recently. All these are putting pressure on the sub strata which all ready under severe pressure, the new industrialised effects of drilling and disturbance of those strata can only exacerbate the situation.

      • Didn’t watch the rubbish. Propaganda.

        Your post is an attempt to lead the casual reader to believe that oil and gas exploration is linked to sinkholes otherwise why bring it to the debate? The article is about water been contaminated, why change the discussion. …. maybe because the article is laughable

        • I didn’t mention the oil and gas industry originally, and nor does the video, it was you that did, then why fly off the handle for a connection only made by you??
          If you didn’t watch it then your comment is pointless anyway isn’t it?
          Never mind, stoney ground, or at least that is the assumption.

          • Your opening post contains “increase in sinkholes across the world may have an effect on any oil and gas exploration.” [Edited by moderator]

            • That comment was that the oil and gas industry should be careful where they drill pennywise, not to blame the oil and gas industry for creating sink holes, though now you come to mention it, that could be another possible reason for sinkholes, thanks for the lead.
              Very impressed by the measured calm and erudite response by the way, very positive and uplifting on this glorious sunny spring Sunday.
              Have a lovely day.

  5. What I find interesting in this article is the lack of balance and accuracy. The following passage is a direct quote from ukog regarding mark wells wood:

    “As part of the Markwells Wood planning application, UKOG has worked with hydrogeology specialists Envireau
    Water, the Environment Agency and Portsmouth Water to arrive at a greatly improved understanding of the
    chalk aquifer that lies adjacent to the site. Future planned drilling will utilise biodegradable natural drilling
    fluids to present zero hazard to the area’s chalk groundwater acquifer.”


    Why has this not been included in the article? I expect the ‘independent’ moderator will request the author amends the article accordingly….. we’re all watching…. or is this site just propaganda to scare the local community?

    • Dear John. Thank you for your comment. If you spool down to the end of the post there is a link to an earlier article (9 March 2017) in which I reported on the revised information provided by UKOG for its Markwells Wood application. Here’s the link if you wish to look at it. https://drillordrop.com/2017/03/09/ukog-submits-new-information-on-south-downs-oil-drilling-consultation-now-open/ This earlier article included a reference to biodegradable drilling fluids and other ways in which UKOG proposes to mitigate any risk to the chalk aquifer. I think this provides balance and accuracy on this issue. I look forward to reading your future comments. Best wishes, Ruth

      • Ruth. My comment was regarding balance and accuracy in THIS article. Reference to an alternative article doesnt do this. Surely the information is fundamental to the discussion HERE.

        It is clear if has been omitted to mislead readers and scare the local community. To be clear, it’s a disgrace and you should be ashamed

        • John
          I am OK with the reporting. I read the earlier article and this one just provides a bit more information. I note that the first article has only one response, but this one has rather more.
          The headlines can be a bit breathless, but that’s reporting for you.

          Perhaps it should have been…..

          Drilling proposal facilitates a better understanding of Karstic drainage issues in the South Downs Chalk.

          A representative of the statutory bodies has thanked UKOG and Markwells Wood Watch in enabling a better understanding of drainage issues in the South Downs Chalk. People now know that any leak directly into a Karstic feature may result in that leak arriving at a spring in a few hours.

          The statutory bodies are now reviewing all spill management measures across the South Downs to ensure they are fit for purpose.


          For drilling, the site is on the clay with flint, so the key issue is a leak from the borehole during production. That would seem well within the expertise of the industry.

          I guess there are some examples of risks outwith drilling that now need reviewing across the South Downs. Petrol stations( leaking Tanks), septic tanks, heating fuel tanks?

  6. At current market environment and low oil price. These companies won’t be able to develop their field so alk their exploration will be worthless. The anti fracking brigades is wasting their time just as much as these companies wasting their investment money drilling that will come to nothing.

    • “As part of the Markwells Wood planning application, UKOG has worked with hydrogeology specialists Envireau
      Water, the Environment Agency and Portsmouth Water to arrive at a greatly improved understanding of the
      chalk aquifer that lies adjacent to the site.”
      And what exactly does that mean, a better understanding? Why have they not included the report itself, or a link to it?
      I find it interesting, that in section 22., Share Based payments, it mentions consultants, but not who they are!
      It is also interesting to find, that the company is being loaned money from a New Jersey based hedge fund manager YA Global Master SPV Ltd., which in turn is managed by Yorkville Advisors, LLC. Who have had class actions taken out against it, for fraud!
      At the end-of-the-day, the Government is still supporting fossil fuels, when we know, it is driving climate change. Then there is not just the issue, of the risk of the Portsmouth area’s water being rendered unfit for human consumption. Along with the increase in methane emissions, a company, heavily in debt, self-regulaltion, increased air and noise pollution.

      • Who says there is a report, you’re reading what you want to read.

        FYI the company doesn’t owe any money on a loan. What does a third party having a fraud case against then have anything to do with Markwells Wood.?

        You need to read the quote I provided ‘zero risk’. Yes, as in less chance than being a truck by lightning. … good odds hey?

        What kind of visual and noise pollution do alternatives like solar and wind cause?

        Why does this site not contain more articles regarding potential contamination to water sources? Anyone would think they aren’t really concerned about the local water supply but that this is just the latest angle to attack oil and gas in the UK. …….

        So to summarise. No debt and no risk. Sounds like a no brainer

  7. John-I think the “independent” moderator is getting some rest before overtime is required!

    The arguments are to the converted-they don’t have to be factual. Bit like the Labour party at the moment. It is far easier than converting the unconverted, but it has a tendency to turn off the unconverted because they don’t like being taken for fools.(The FOE debacle demonstrates the approach, and the weakness.)

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