CA2048503C

CA2048503C - Method and apparatus for protecting an environmental monitoring well head

Info

Publication number: CA2048503C
Application number: CA 2048503
Authority: CA
Inventors: Donald A. Kenner
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-08-10
Filing date: 1991-08-06
Publication date: 1995-04-11
Anticipated expiration: 2011-08-06
Also published as: CA2048503A1

Abstract

An environmental monitoring well housing and protection method. A housing is disposed over the end of an environmental monitoring well pipe and set in concrete along with the well pipe itself so that the space between the housing and the well pipe is filled with concrete below the end of the well pipe. Fins extend outwardly from the housing into the concrete to anchor the housing. The housing has an interior ledge for receiving and supporting a cover. A flexible gasket is placed on the ledge, the cover is placed on the flexible gasket, and the two are fastened down by a pair of bolts that screw into threaded bores in the ledge. The bolts have five-sided heads and a special tool is provided for installing and removing them.
The cover thickness is substantially the same as the distance from the top of the housing down to the ledge, so that where the top of the housing is mounted flush with the ground the top of the cover is also flush with the ground.
The cover includes recesses for the heads of each of the bolts, so that the resultant well head is entirely flush with the surface of the ground. The flexible gasket has an adhesive material on its underside for attachment to the ledge. Apertures in the cover through which the bolts extend are sized to receive a tip of the special tool for use in lifting the cover.

Description

-1- 2û~8S03 METHOD AND APPARATUS FOR
PROTECTING AN ENVIRONMENTAL MONITORING WELL HEAD

Background of the Invention S ., This invention relates to devices and methods for housing and protecting well heads, particularly for housing and protecting the heads of environmental monitoring wells while permitting convenient access thereto.
It has become a common practice to install monitoring wells in the ground in areas where the ground water is at risk of contamination. Such wells, known as environmental monitoring wells, are typically installed, - 15 for example, around the periphery of solid waste landfills or where there has been, or there is a potential for, a hazardous or toxic chemical spill. Water is periodically extracted from the wells and tested for the presence of contaminants.
Basically, environmental monitoring wells are just pipes installed vertically in the ground, extending to various depths and terminating at a well head near the surface of the ground. Typically, there is no substantial permanent equipment located at the well head; it is simply capped between usages. In some cases there may be a small monitoring device installed at the well head. There is ordinarily no attendant at the well head; it is only visited periodically to extract water for tests or, in some cases, to check a small monitoring device.
There is a risk that an environmental monitoring well can itself become a source of contaminants. This will happen if surface water containing contaminants, or an undiluted contaminant itself, is allowed to enter the well pipe. This can occur, for example, if there is uncontainedsurface water adjacent the well head at the time that it is uncapped for testing, or where the cap is not -2- 2~48503 ~ adequately sealed. It can also occur where part of the well head protrudes above the surface of the ground and is damaged by the movement of vehicles or heavy equipment, leaving the interior of the well pipe exposed in a manner that permits the introduction of contaminants. It is important to ensure that this does not occur.
In order to minimize the likelihood that environmental monitoring wells will contaminate the very water they are installed to test, it is desirable, if not required, to provide them with a fluid resistant housing in addition to the well cap itself; indeed it is desirable to provide a housing that is impervious to water and other fluids, i.e., fluid-tight. Known housings typically extend above the surface of the ground and provide a cover that is less than fluid-tight. For example, Ames et al. U. S.
Patent No. 4,669,536 discloses a protective housing disposed around the end of a monitoring well pipe, set in concrete and having a hinged cover on top. But, the housing extends above the surface of the ground where it can interfere with, and be damaged by, the movement of vehicles and equipment. There is no provision for making the hinged cap fluid-tight.
In addition, various types of caps are available for sealing pipes in general. Delahanty U. S. patent No.
759,081 shows a cap which, together with a gasket, is fastened to the end of a pipe by bolts. Baker et al. U. S.
Patent No. 3,473,573 and Forsburg U. S. Patent No. 1,509,643 disclose well caps which are also fastened with bolts and include gaskets. Rooney U. S. Patent No. 3,856,050 and Richardson U. S. Patent No. 3,942,681 show flange protectors for placement over the ends of flanged pipes. However, none of these devices is, or could readily be, adapted to provide a fluid-tight cover for an environmental monitoring well that is in addition to the well pipe cap itself and is flush with the ground.

_ -3- 2048503 It has also been found that frost can dislodge a well housing, thereby breaking the seal and opening the well bore to contamination. When the environmental monitoring well is located in a location accessed or accessible by the public, there is a need for a well head housing that is resistant to tampering or vandalism by unauthorized personnel. Such actions can also destroy the integrity of the housing and allow contaminants to enter the well bore.
Therefore, it can be seen that there is a need for a new and improved environmental well housing that minimizes the risk of contamination of the ground water which the well is installed to monitor.
-Summary of the Invention The present invention meets the aforementionedneed for an effective environmental well housing, and overcomes the drawbacks of currently available devices, by providing, in a preferred embodiment, a housing that is in addition to the well pipe cap itself, is flush to the ground, and is fluid-tight. An enclosure is disposed over the end of the well pipe and set in concrete along with the well pipe itself, so that the space between the enclosure and the well pipe is filled with concrete below the end of the well pipe, thereby sealing out contaminant fluids from below. The housing has an interior ledge for receiving and supporting a cover. A flexible gasket is placed on the ledge, the cover is placed on the flexible gasket, and the two are fastened down by a pair of bolts that screw into threaded bores in the ledge, thereby providing a fluid-tight seal for the top of the well. The cover thickness is substantially the same as the distance from the top of the enclosure down to the ledge, so that where the top of the enclosure is mounted flush with the ground the top of the cover is also flush with the ground. This _4_ 204850~
~ arrangement produces a fluid-tight chamber for access to the upper end of the well pipe.
The cover includes recesses for the heads of each of the bolts, so that the resultant well head assembly is entirely flush with the ground surface. The rubber gasket has an adhesive material on its underside for attachment to the ledge, thereby ensuring that it will stay in place as the cover is attached and removed from time to time.
The cover has apertures for receiving the bolt shaft that is threaded into the threaded bores of the ledge. The apertures are larger than the outer diameters of the bolts for receiving a rod end of an opening tool.
The rod end is too large to fit into the ledge bores, thereby facilitating lifting of the cover from the enclosure without damaging the bore threads. Further the bolt preferably has a nonstandard head, such as with five sides, in order to deter unwanted tampering. The enclosure outer surface also has fins that project outwardly for anchoring it into the concrete.
Therefore, it is a principal objective of the present invention to provide a novel and improved environmental monitoring well housing and protection method.
It is another objective of the present invention to provide an environmental monitoring well housing that is in addition to the well pipe cap itself.
It is a further objective of the present invention to provide an environmental monitoring well housing that is tamper-proof.
It is also an objective of the present invention to provide a tool for facilitating opening a cover of the tamper-proof housing.
It is yet another objective of the present in~ention to pro~ide an en~ironmental well housing that is anchored into the well head.
It is a feature of the present invention that it provides a cover having apertures that a fastener, such as ~5- 20~850~
a bolt, passes through having a diameter accommodating a tool for lifting the cover.
It is another feature of the present invention that it includes the fastener or bolt with a nonstandard head.
It is a further feature of the present invention that it employs an enclosure on which the aforesaid cover seats, and has an anchor that secures the enclosure in the well bore.
It is yet a further feature of the present invention that it provides a tool that engages the nonstandard bolt head and has a rod end that is received in a cover aperture for lifting the cover.
The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.

Brief Description of the Drawings Figure 1 is a cross section of a preferred embodiment of the environmental monitoring well housing of the present invention, installed in the ground together with an environmental monitoring well.
Figure 2 is an end view of the enclosure of the housing of Figure 1 as viewed from the bottom of that figure.
Figure 3 is an isometric view of a tool usable for installing and removing the housing cover of Figure 1.
Figure 4 is a fragmentary partial cross section showing the housing of Figure 1 being opened with the tool of Figure 3.

Description of the Preferred Embodiment An overview of a preferred embodiment of the environmental monitoring well housing of the present ~ T
.

~ invention installed in the ground at the head of a well is shown in Figure 1. The well comprises a cylindrical pipe 10 disposed vertically, and extending down, in the ground for accessing ground water at a selected level. The well pipe is disposed at the center of a bore 12 in the ground 14, and surrounded by concrete 16 to a predetermined depth. Various other packing materials are typically disposed below the concrete. The top of the pipe is ordinarily closed by a cap 18, which is typically just a cup-shaped device that is pressure fit onto the pipe 10, though it may be attached by a variety of other means.
The environmental well housing 20 comprises an enclosure 22 disposed around the well pipe 10 at the top thereof and set in the concrete 16 along with the well pipe so that the concrete fills the space between the inside of the enclosure and the outside of the well pipe. A cover 24 fits within the enclosure 2 at the top thereof so as to provide a substantially flat top surface. A flexible gasket 26 is disposed between the cover 24 and the enclosure to provide a fluid-tight assembly. The cover and gasket are attached firmly to the enclosure by a pair of bolts, such as bolt 28. Bolts 28 have standard threaded shanks, but have nonstandard heads 30. Although any nonstandard configuration could be used, the preferred form is a five-sided head instead of a standard four or six-sided head. This makes it difficult to open with a conventional socket or other wrench.
The enclosure is mounted in the ground with a portion 32 of the concrete 16 surrounding the outside of the enclosure so that the upper surface of the entire assembly is substantially flush with the ground leve 34 when the cover 24 is installed. Inside the enclosure the concrete 16 rises a few inches above the bottom of the enclosure to a level 36 several inches below the top of the well pipe 10.

~ The enclosure 22 of the well housing pre~erably, though not necessarily, comprises cylindrical sections, as shown by the bottom view of Figure 2. It has an upper section or end 38 of a first diameter, a lower section or end 40 of a second, smaller diameter, and a central section 42 that tapers from the upper section 38 to the lower section 40. The upper section provides an upper opening 44, and the lower section provides a lower opening 46. An inwardly-protruded ledge 48 is inside the enclosure, disposed above the central section 42, for supporting the flexible gasket 26 and the cover 24.
Preferably, the enclosure 22 and cover 24 are made of cast and machined aluminum.
The outer periphery of the gasket 26 and the cover 24 are shaped to fit just within the inner wall of the upper section 38 of the enclosure 22. Thus, in the case of an enclosure having cylindrical sections, the cover 24 is disc shaped and the gasket 26, like the upper surface of the ledge 48, is ring shaped.
The gasket 26 has a top portion 50 made of a flexible material, such as rubber, to seal the ioint between the cover 24 and ledge 48 when compressed. It also has a bottom portion 52 comprising an adhesive backing for attaching the gasket 26 to the ledge 48 so as to retain the gasket in place when the cover is installed and removed from the enclosure from time to time.
The cover has an upper surface 54 and a lower surface 56, and a pair of recesses 58 and 59 in the upper surface for receiving the heads of bolts 28. The lower surface 56 may, but need not necessarily, include an offset 60. Thence, when the cover is installed the bolt heads are disposed below the upper surface of the cover so that the entire assembly is substantially flush with the surface of the ground. The ledge has a pair of threaded bores 62 and 63 for receiving the bolts 28 so that the cover may be firmly fastened to the enclosure. The _ -8- 204850~
gasket 26 has a pair of apertures 64 and 65 for allowing the bolts to pass therethrough. The cover 24 also has a pair of apertures 66 and 67 having a diameter slightly larger than the diameter of bores 62 and 63. More than two bolts may be used, if desired, to ensure that the fluid-tight seal is not broken. In any event, the bolts should be disposed symmetrically around the periphery of the housing.
As shown in Figures 1 and 2, enclosure 22 has a vertical outer surface 68 in the lower section 40 from which a pair of protrusions or fins 70 and 71 extend radially outwardly in opposite directions. These fins are preferably plate-like and disposed close to lower opening 46. These fins extend only partially around the enclosure so that the enclosure can be placed in concrete and the concrete will flow up along outer surface 68 between the fins. In order to assure that the fins are embedded in the concrete, the enclosure can be rotated about the longitudinal axis 72 of the enclosure and retained in this position until the concrete cures.
Fins 70 and 71 serve as anchors for securing the enclosure in the concrete, and therefore in the well head.
These anchors prevent the lifting or dislodging of the enclosure, due to winter freezing conditions or possibly even vandalism.
Referring now to Figure 3, a special tool 74 is provided by the invention to accommodate the installation and removal of cover 24 from enclosure 22. The tool has a general T-shape, with the bottom or foot end 76 having a socket wrench 78 sized to conform to the five-sided bolt heads 30. Recesses 58 and 59 allow insertion of the wrench 78 onto the bolt head during use.
A shank 80, also functioning as a handle, extends from end 76 to an opposite end 82. The cross of the T-shape of the tool is formed of a rod member 84 having opposite ends 86 and 88. ~ember 84 is used as a handle -9- 20q~503 s_ when wrench 78 is being used. The rod member is fixed to shank 80 at an intermediate portion 90. Ends 86 and 88 are sized for sliding receipt in apertures 66, but are too large to fit into enclosure bores 62. Also, the ends are preferably rounded to facilitate insertion in the apertures of the cover. The size of rod member ends 86 and 88 prevents the rod member ends from damaging the enclosure bores while providing for lifting of the cover out of opening 44.
As shown in Figure 4, this lifting capability is provided by inserting one of the rod ends into one of the cover apertures after the bolts have been removed. A
lifting force is then applied to shank or handle 80, as ~- represented by arrow 82. The leveraged or angular force applied by the rod end on the cover in the aperture produces sufficient friction to hold the rod end in the aperture while the cover is lifted.
In use, the housing is installed in the well head along with the well pipe as shown in Figure 1. The gasket 26 is placed in the enclosure 22 on the ledge 48, the cover 24 is placed in the enclosure on top of the gasket, as has been described with reference to tool 70 and Figure 4, and the bolts 28 are screwed into the bores 62 and 63 and tightened down. Thereafter, vehicles and machinery can be moved over the well head without obstruction or damage to the housing, which might otherwise break the fluid-tight seal. To access the well pipe for testing the ground water the bolts are removed and the cover is lifted away using tool 70.
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow.

Claims

1. In an environmental monitoring well having a well pipe disposed in a well bore with an upper end thereof extending toward the surface of the earth, a housing comprising:

(a) an enclosure having an upper opening and a lower opening, said enclosure being of unitary con-struction and being disposed in said well bore around said upper end of said well pipe, said upper opening of said enclosure being substan-tially flush with said surface of the earth;

(b) closure means, adapted to be disposed within said enclosure at said upper opening thereof, for closing said upper opening and preventing fluid from entering therethrough, said closure means having a substantially flat upper surface flush with said upper opening of said enclosure when installed therein; and (c) sealing means disposed in said well bore between the outer surface of said well pipe and the inner surface of said enclosure so as to partially fill the space therebetween, said sealing means comprising a material distinct from said well pipe and said enclosure, said material having a characteristic that allows it to flow into the space between the outer surface of said well pipe and the inner surface of said enclosure and assume a stable condition so as to seal off the space therebetween.

2. The housing of claim 1, wherein said enclosure has an outer surface extending between said upper and lower ends, and said anchoring means includes a protrusion extending outwardly from said outer surface, and sealing means disposed in said well bore between said outer surface of said enclosure and the inner surface of said well bore so as to fill the space therebetween sufficiently to cover said protrusion.

3. The housing of claim 2, further comprising fastener means for attaching said cover to said enclosure such that said cover is disposed between said ledge and said upper opening.

4. The housing of claim 3, wherein said fastener means comprises a plurality of bolts having respective bolt heads, said enclosure includes a plurality of threaded bores in said ledge for receiving and engaging said bolts, and said cover includes a plurality of apertures there-through for receiving said bolts and a plurality of corre-sponding recesses in said upper surface for receiving said bolt heads.

5. The housing of claim 2, wherein said closure means further comprises a flexible gasket having a shape substantially identical to the shape of said ledge and adapted to be placed between said cover and said ledge.

6. The housing of claim 5, further comprising a plurality of bolts having respective bolt heads, a plural-ity of corresponding threaded bores in said ledge for receiving and engaging said bolts, a plurality of corre-sponding apertures in said gasket for receiving said bolts, a plurality of corresponding apertures in said cover for receiving said bolts, and a plurality of corresponding recesses in the upper surface of said cover for receiving the heads of said bolts.

7. The housing of claim 5, wherein said gasket includes an adhesive backing for attachment to said ledge.

8. The housing of claim 7 wherein said enclosure comprises cylindrical portions.

9. The housing of claim 8, wherein said enclosure has an outside diameter at said upper opening that is greater than its outside diameter at said lower opening.

10. The housing of claim 7 further comprising means for anchoring said enclosure in said well bore.

11. The housing of claim 10, wherein there is space between the outer periphery of said enclosure at the upper opening thereof and the inner surface of said well bore, and a first section of said sealing means is disposed between said outer periphery of said enclosure and said inner surface of said well bore, said upper opening of said enclosure and said first section of said sealing means being substantially flush with the surface of the ground, and a second section of said sealing means between the outer surface of said well pipe and said enclosure is disposed below the upper end of said well pipe.

12. A method for housing and protecting an environ-mental monitoring well having a well pipe disposed in a well bore with an upper end extending toward the surface of the ground, comprising:

(a) placing an enclosure in said well bore around said upper end of said well pipe, said enclosure being of unitary construction and having an upper opening, a lower opening and an inwardly-protrud-ing ledge between said upper opening and said lower opening;

(b) placing sealing means in said well bore between the outer surface of said well pipe and the inner surface of said enclosure, said sealing means being a composition distinct from said well pipe and said enclosure and having a characteristic that allows it to flow into the space between the outer surface of said well pipe and the inner surface of said enclosure and assume a stable condition so as to seal off the space therebetween;

(c) placing on said ledge a flexible gasket having a shape substantially identical to the shape of the surface of said ledge;

(d) placing on said gasket within said enclosure a cover having an upper surface and a peripheral shape substantially identical to the shape of the interior of said enclosure; and (e) attaching said cover to said enclosure so that said upper opening of said enclosure and said upper surface of said cover are substantially flush with the surface of the ground.

13. The method of claim 12, wherein said attaching step is accomplished using fastener means disposed beneath said upper surface of said cover.

14. The method of claim 12, wherein said attaching step is accomplished using bolts disposed through said cover and said gasket and engaging said ledge of said enclosure.

15. The method of claim 12, wherein said enclosure comprises cylindrical sections.

16. The method of claim 12, wherein said enclosure has an outside diameter at said upper opening that is greater than its outside diameter at said lower opening.

17. The method of claim 12, wherein said gasket is adhesively attached to said ledge.

18. In an environmental monitoring well having a well pipe disposed in a well bore with an upper end thereof extending toward the surface of the earth, a housing comprising:

(a) an enclosure having an upper opening and a lower opening, said enclosure being disposed in said well bore around said upper end of said well pipe;

(b) closure means, adapted to be disposed within said enclosure at said upper opening thereof, for closing said upper opening and preventing fluid from entering therethrough, said closure means having a substantially flat upper surface flush with said upper opening of said enclosure when installed therein; and (c) sealing means disposed in said well bore between the outer surface of said well pipe and the inner surface of said enclosure so as to partially fill the space therebetween, said sealing means comprising a material distinct from said well pipe and said enclosure, said material having a characteristic that allows it to flow into the space between the outer surface of said well pipe and the inner surface of said enclosure and assume a stable condition so as to seal off the space therebetween said sealing means being further disposed between the outer surface of said enclosure and the inner surface of said well bore, and beneath said enclosure, so as to seal off the space therebetween the outer surface of said enclosure and the inner surface of said well bore, and extending substantially continuously from inside said enclosure, beneath said enclos-ure, to outside said enclosure.

19. A method for housing and protecting an environ-mental monitoring well having a well pipe disposed in a well bore with an upper end extending toward the surface of the ground, comprising:

(a) placing an enclosure in said well bore around said upper end of said well pipe, said enclosure having an upper opening and a lower opening and an inwardly-protruding ledge between said upper opening and said lower opening;

(b) placing sealing means in said well bore between the outer surface of said well pipe and the inner surface of said enclosure, said sealing means being a composition distinct from said well pipe and said enclosure and having a characteristic that allows it to flow into the space between the outer surface of said well pipe and the inner surface of said enclosure and assume a stable condition so as to seal off the space there-between;

(c) placing on said ledge a flexible gasket having a shape substantially identical to the surface of the ledge;

(d) placing on said gasket within said enclosure a cover having an upper surface and a peripheral shape substantially identical to the shape of the interior of said enclosure;

(e) attaching said cover to said enclosure so that said upper opening of said enclosure and said upper surface of said cover are substantially flush with the surface of the ground; and (f) placing said sealing means between the outer surface of said enclosure and the inner surface of said well bore, and beneath said enclosure, so as to seal off the space between the outer surface of said enclosure and the inner surface of said well bore, said sealing means extending substantially continuously from inside said enclosure, beneath said enclosure, to outside said enclosure.