The Problem.

It starts like this: contamination on land migrates downwards into the sub-soil, aided by time, snow and rain. The contaminants pollute the soil and groundwater in both the saturated and unsaturated zones.

The saturated formation, or aquifer, normally has considerable area— but minimum thickness. Thus, it is difficult to access by conventional vertical wells because of the low screen area in contact with the ground water dictated by the small aquifer thickness.

Furthermore, the relatively slow movement of groundwater obviously restricts the rate at which water can be drawn into a vertical well, preventing rapid arrest of contaminants plume movement.

The Solution.

A horizontal well placed in the groundwater exposes a large area of screen to the aquifer, which can influence the groundwater flow along its entire length. To date Longbore has installed horizontal wells in a wide variety of sites, which have proven to be extremely effective in extracting free and dissolved phase contaminants.

Both DNAPLs and LNAPLs can be removed utilizing horizontal wells. The precision placement of wells within the sub-surface geology permits maximum well efficiency to be achieved. The same technology enables air sparging, soil vapor extraction and bio-remediation processes to be used to treat both the saturated and unsaturated zones of the formation. Screen lengths of over 1,000’ have been installed at depths in excess of 200’.

The Proof.

Longbore has demonstrated that our horizontal well can replace twenty to seventy vertical wells, depending on the geology of the site. The photograph opposite shows how five horizontal wells replaced 224 vertical wells on an estuarial site contaminated with DNAPL wastes.

Horizontal remediation wells have been installed in sites where the geology has ranged from unconsolidated sand, gravel, clay and glacial till to fractured bedrock.

Minimum Impact, Maximum Effect.

Longbore has developed market leadership in the design and installation of “blind” wells. These wells are drilled and completed from the entry point rather than the conventional construction methods which are drilled to exit on the surface, opened up and then completed by pulling the well assembly into the borehole from the exit back to the entry.

Blind wells allow screen to be placed under offsite properties with minimum impact during drilling and installation, with no permanent surface disruption, other than the well head.