Specialist in Geothermal drilling, water well drilling and mini pilling

About Gretton Site Investigations Ltd.


GSI has been established for 15 years, our company runs 7 Mesenza MI6 drilling rigs. Our company Specialises in drilling geothermal bore holes up to 210m and water wells up to 260m.

Over the last 15 years GSI has drilled all over the United Kingdom, we have completed some of the largest GSH projects in the country for example Bow cliff Manor 72 x 140 m bore holes, we have drilled many projects domestic and commercial in the Channel Islands.

We are capable of drilling a single bore hole in your back garden to mobilising 7 rigs to a building site.

Over the last 3 years we have completed and still ongoing drilled 19 projects for a very established Retirement Home Builder throughout the country, averaging 22 x 150m bore holes on each site and a site drilling average of 4 weeks per site using I to 3 rigs on each site, from North Yorkshire to Newquay, with our experienced personnel and equipment we can complete these projects within our customers tight building time.

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Our services

Geothermal Drilling

One meter below the surface throughout the UK the average temperature is 12 degrees, your building will be engineered to determine the size of kilowatt heat pump  your building requires...
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Water well drilling

Anyone with in the United Kingdom is allowed to drill a water well on their private land and extract 20,000ltr/day, with out an extraction license.   GSI have drilled many water wells...
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Mini Piling Drilling

GSI have adapted their drilling rigs to Auger pile up to 300mm piles and to the depth of 20m, depending on ground conditions, our rigs are very maneuverable around site...
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What our clients say


Gretton Site Investergstion has drilled me a water bore hole on my property in Bourne End for irrigating and domestic use. I was recommended this company from a friend, they are very professional, friendly and was the only company I could find that would complete the total project, from geology to connecting to my existing water system. Tijl.

Tijl , 07.07.2020.

We have used GSI to drill our private water well behind our house. We are delighted with the work they have done. When our Water Well was completed you could hardly tell that there was a drilling machine in our back yard. They left everything clean and tidy. If anyone looking to drill a water well I would highly recommend these guys. Great work. R. Allan

Roy Allan , 08.03.2019.

We have used GSI for all of our geothermal bore hole drilling projects for the past 7 years. We find GSI totally dependable, honest and never go back on their price, even in tough ground conditions.

Alastair Murray, The Renewable Design Company , 09.03.2016.

Gretton Site Investergation has drilled several GSH projects for us in central London, they have just completed an 11 x 150m project in a very restricted area in central London. We find them very experienced and hard working, their equipment is well maintained, method statements and HSE requirements are all covered. And I am looking forward to working with them on our next project.

Pat Sterling, Knight Build , 08.09.2016.