FIELD

Exemplary embodiments are directed to mechanical devices and systems. More particularly, exemplary embodiments are directed to a device and system for facilitating the analysis of samples of sub-slab soil gas.

INTRODUCTION

This section provides background information related to the present disclosure which is not necessarily prior art.

The potential for volatile organic compounds (VOCs) associated with contaminated soil and groundwater to enter homes and businesses through basements and building slabs is a recent focus of federal and state environmental protections agencies. This potential route of exposure is commonly referred to as the “vapor intrusion pathway.” Evaluations of the potential risk associated with long-term exposure to VOCs have been published by the United States Environmental Protection Agency (EPA) and other entities. These evaluations indicate that very low concentrations of some of these VOCs, on the order of a few parts per billion in some cases, can pose an unacceptable risk to building occupants. In some situations, sub-slab soil gas samples are collected to evaluate vapor concentrations and the potential for these vapors to enter a building.

The science of analyzing samples of sub-slab soil gas is known. However, the practicalities of collecting these samples of gas are quite cumbersome. Techniques and devices currently used and proposed in recent draft guidance documents by the EPA and other agencies to collect sub-slab soil gas samples are built upon the experience of environmental professionals gained over many years of sampling groundwater via monitor wells. In essence, the current state of the art for sub-slab sampling is the use of a miniature well installed through the slab. These wells, or “sub-slab vapor points” are typically installed by boring a fairly crude hole through the slab and cementing a metal tube in place. At the top of the tube are a number of threaded fittings that allow the vapor point to be connected via plastic tubing to an evacuated vessel, known in the art as a summa canister.

Because the levels of concern for many of the VOCs are so low, leaks in the vapor point fittings or along the edge of the vapor point itself allow indoor air to dilute the sample, rendering the sample useless. This situation is exacerbated by the fact that most vapor points must be sampled on multiple occasions. Each time the vapor point is used it must be disconnected and reconnected using multiple wrenches, usually in tight quarters. This activity can cause some fittings to progressively loosen and leak more readily, or result in the point itself losing its bond with the cement used to anchor it during installation. Federal and state EPA officials recognize this shortcoming and have developed elaborate, time consuming methods for detecting such leaks.

The collection of sub-slab samples can also be inconvenient to building occupants since it requires the removal of floor coverings and coring or drilling of the foundation slab. One recommended method is using an electric hammer drill or rotary hammer to produce an inner pilot hole into the concrete slab. After the pilot hole is drilled, an individual must drill an outer hole to a predetermined depth using a larger drill bit. After the outer hole is finished, the individual must use the original tool to assure that the pilot hole is then drilled through the slab and several inches into the sub-slab material. Once the drilling is completed, a stainless steel probe is assembled and inserted into the pre-drilled hole. The probe is mounted as flush as possible with the surrounding slab to minimize the interference with pedestrian or vehicular traffic. The probe has to be cemented into place to ensure that the probe assembly is air-tight with the foundation slab. Since the cement has to cure, an individual must come back at least one further time before sampling of the sub-soil may occur, further inconveniencing a homeowner or business.

Attempts have been made to overcome these and other difficulties inherent in the task of collecting sub-slab soil gas samples for analysis. Various devices and systems have been developed for use in such collection, for instance those previously described in U.S. Pat. No. 8,220,347 and U.S. patent application Ser. No. 13/551,213, both co-owned by the applicant and the fully incorporated herein by reference. Those references disclose invented devices, systems and their methods of use that facilitate the collection of sub-slab soil gas samples by, in part, eliminating the intrusion of the collection system on the interior building space, reducing the potential for damage to the slab introduced by previously used methods of collection, reducing or eliminating the risk of leakage during sampling thereby increasing testing efficacy/efficiency, and reducing collection costs through the introduction of reusable system components, for instance.

However, it has been found that certain disadvantages and drawbacks remain in the current state-of-the-art devices and systems. For example, variations in slab, bedding and foundation thicknesses, and in geographic structures of various testing locations have resulted in a need for sub-slab soil gas collection at variable depths relative to the top surface of a particular slab. Furthermore, as the art of sub-slab soil gas analysis continues to advance, soil gas collection may be needed at an increasing variety of depths relative to the top surface of a given slab. In some instances, drilling well into the backfill or native material beneath a slab to a desired depth for collection is found to increase the potential for clogging or the introduction of undesirable particulates into the vapor stream entering the sampling device.

In some cases, it may be desirable to introduce an external sampling device or probe into a space beneath a slab. Currently known sampling systems, however, either are not compatible with such sampling devices or require invasive installation techniques that are cumbersome, undesirable, and often cause unwanted damage to the slab or structure.

What is desired are devices and systems that eliminate some or all of the drawbacks of the known devices and techniques for measuring sub-slab soil gas. Providing a leak-resistant device that allows for prompt installation and removal, saving time and money may eliminate some or all of these drawbacks. Also, a device and system that allows for installation to occur in one appointment is desirable. Such a device may also be designed for use with different VOC measuring devices, both above- and below-slab, and with other sampling devices generally. There is also need for a system that provides some or all of these advantages in addition to the ability to collect samples at a point beneath the slab, and without clogging or contamination of the device and sample, respectively. No known references, taken alone or in combination, are seen as teaching or suggesting the presently claimed apparatus for use in the sampling of sub-slab soil gas.

SUMMARY

Exemplary embodiments of the device may eliminate some or all of the aforementioned drawbacks of the current art. Exemplary embodiments of the system components may be machined from a single piece material, such as brass or stainless steel, eliminating the need for multiple fittings and thereby reducing the number of potential leaks. Exemplary embodiments of the system may be installed into a one-inch diameter hole cored through the slab of concrete or other foundation material. The cored hole provides a smoother bonding surface and can be accomplished using a standard, hand-held coring machine. Exemplary embodiments of the system may be driven into the cored hole using a hammer or similar device. Installation of exemplary embodiments of the system forces flexible silicone tubing located on at least a portion of the exterior surface of an adaptor body against the interior wall of the cored hole, effectuating an air-tight, or almost air-tight, seal between the cored slab and the device. Exemplary embodiments of the adaptor body of the system may then be connected to a portion of sampling tubing via an air-tight barbed fitting.

Exemplary embodiments of the system include an adaptor body having a length and proximal and distal ends. The adaptor body includes a first barbed portion disposed at the proximal end of the adaptor body, a second barbed portion disposed at the distal end of the adaptor body, a collar portion disposed between the first and second barbed portions, an internal cavity having an interior surface and passing through the length of the adaptor body, and a coupling portion having an internal thread disposed on the interior surface of the internal cavity and extending longitudinally thereon from the distal end of the adaptor body.

On object of the innovation is to provide a system that can be used to collect sub-slab soil gas at varying depths with respect to the top surface of a given slab, without necessitating the manufacture of adaptor body components having many different lengths. Another object of the innovation is to provide a system that can be used to collect sub-slab soil gas at points beneath the give slab without introducing particulates into the vapor stream being collected, and without increasing the potential for clogging occurring in the cavities of the system. Exemplary embodiments of such a system include an extension having a length a first and second ends. The extension has an internal cavity extending longitudinally through the extension from the first end of the extension to an outlet at the second end of the extension, and an external thread disposed at the first end of the extension adapted for complimentary threaded retention within the coupling portion of the adaptor body.

In some embodiments, the extension is a fitting extension having a fitting portion disposed at the outlet. The fitting extension may be, for instance a barbed portion disposed at the outlet, wherein one or more generally frustum shaped barbs are disposed thereon whereby other down-hole sampling devices may be attached to the system directly or indirectly, for instance via stainless steel or rigid or flexible plastic tubing. Some exemplary embodiments include an external engaging portion disposed between the external thread and the barbed portion of the fitting extension. The external engaging portion may have a lateral cross-sectional shape adapted for use with a tool such as a wrench to tighten or loosen the connection between the extension and the adaptor body.

In some exemplary embodiments of the system, the extension is a filter extension having a filter element disposed at the outlet. The filter element may, for instance, include a filter element having an attachment aperture and at least one internal rib disposed within the attachment aperture, and a barbed portion having at least one barb disposed at the outlet, wherein the barbed portion is retained within the attachment aperture of the filter element by complimentary engagement between the at least one internal rib and the at least one barb. In some embodiments, the filter element is formed of a sintered porous metal. Exemplary embodiments of the system may include a filter extension having an external engaging portion disposed between the external thread and the barbed portion of the filter extension. The external engaging portion may, for instance, have a lateral cross-sectional shape adapted for use with a tool such as a wrench to tighten or loosen the connection between the filter extension and the adaptor body.

Further exemplary embodiments of the system may be provided wherein the extension is a sieve extension having a plurality of lateral outlets wherein each lateral outlet intersects with the internal cavity of the sieve extension. In some embodiments, the sieve extension may include an external engaging portion disposed at its second end. The external engaging portion may, for instance, have a lateral cross-sectional shape adapted for use with a tool such as a wrench to tighten or loosen the connection between the sieve extension and the adaptor body. In some embodiments, the external engaging portion has a length and a circular cross-sectional shape with two opposing parallel sides. One object of the system is to provide lateral gas passageways by way of a plurality of lateral outlets. In some embodiments, the plurality of lateral outlets has at least one pair of outlet cavities extending laterally through the engaging portion in an intersecting “X” pattern. In preferred embodiments, the lateral outlets are provided as three pair of outlet cavities extending laterally through the engaging portion, wherein each pair is configured in an intersecting “X” pattern.

Another object of the present innovation is to provide a system for sampling sub-slab soil gas wherein the outlet or outlet(s) may be positioned at variable depths and even beneath a slab. A further object is to provide such ability without requiring the manufacture of a wide variety of adaptor bodies having differing lengths. In some embodiments, the adaptor body and extension are further provided with a length extension having first and second ends coupled to and between the adaptor body and extension. The length extension has an internal cavity having an interior surface extending longitudinally through the length extension from the first end to the second end, an external thread disposed at the first end adapted for complimentary threaded retention within the coupling portion of the adaptor body, and a coupling portion having an internal thread disposed on the interior surface and extending longitudinally thereon from the second end of the length extension, wherein the internal thread is adapted to threadably retain the external thread of the extension. The installation of an embodiment of the invented system having an adaptor body, length extension and extension such as a fitting extension, filter extension or sieve extension, for instance, allows for the collection of soil gas samples via a continuous internal cavity having one or more outlets wherein the soil gas may enter and travel to the proximal end of the adaptor body for analysis.

An exemplary embodiment of the device may be associated with an automated installation device. Such a device may be robotic in nature, or may be another type of automated device. Alternatively, an exemplary embodiment of the device may be employed by an individual to manually install the device, such as by a hammer.

It is an object of this innovation to provide a system for use in the collection of sub-slab soil gas of the type generally described herein, being adapted for the purposes set forth herein, and overcoming disadvantages found in the prior art. These and other advantages are provided by the innovation described and shown in more detail below.

In another aspect of the innovation, a soil gas collecting device is disclosed that includes a first body portion having a first barbed end and a male connection mechanism, a second body portion having a second barbed end and a first female receiving mechanism that receives the male connection mechanism, a grip portion that facilitates the attachment and removal of the first body portion from the second body portion, and an internal cavity axially extending the length of both the first body portion and the second body portion that allows soil gas to flow through the first body portion and the second body portion.

In another aspect of the innovation, the second body portion includes a threaded collar disposed at a first end of the second barbed end portion that facilitates the installation and removal of the device, the threaded collar including at least one thread having oppositely disposed flat surfaces that facilitates prevention of rotation of the second body portion after installation.

In another aspect of the innovation, the second body portion includes a smooth collar disposed at a first end of the second barbed end portion that facilitates the installation of the device. The smooth collar may further include oppositely disposed flat surfaces to facilitate the prevention of rotation of the second body portion after installation. The second body portion includes no more than two barbs, which facilitate the installation of the device in thin slabs. The barbs may be surrounded by a sleeve to create a seal between the device and the slab.

In another aspect of the innovation, the second body portion includes a projection portion disposed at a second end of the second barbed end and including a second female receiving mechanism that receives an extension. The projection portion includes a first cylindrically shaped projection and a second cylindrically shaped projection having a diameter that is larger than a diameter of the first cylindrical projection, and wherein the second cylindrically shaped projection includes a beveled edge that facilitates installation.

In another aspect of the innovation, a soil-gas collecting device is disclosed that includes a cylindrical body having a length and first and second ends, comprising: an internal cavity having an interior surface and passing through the length of the cylindrical body; and a collar portion disposed between the first end and the second end of the cylindrical body. The collar portion including a first cylindrical shaped projection and a second cylindrical shaped projection having a diameter that is smaller than the diameter of the first cylindrical projection. The second end of the cylindrical body facilitates the piercing of and the sealing to a vapor barrier. The internal cavity extending the length of the cylindrical body allows soil gas to flow from underneath the vapor barrier through the internal cavity. The collar portion of the cylindrical body is adapted to allow the installation of an adaptor body. The adaptor body includes a length and proximal and distal ends and comprising: a first barbed portion disposed at the proximal end of the adaptor body; a second barbed portion disposed at the distal end of the adaptor body. A collar portion is disposed between the first barbed portion and the second barbed portion. The adaptor body also includes an internal cavity having an interior surface and passing through the length of the adaptor body; and a coupling portion comprising an internal thread disposed on the interior surface and extending longitudinally thereon from the distal end of the adaptor body. In addition to gas collection, the cylindrical body facilitates the collection of sub-slab pressure readings.

Yet another aspect of the innovation includes an installation device for receiving and installing an adaptor body for sampling soil gas under a slab, where the slab has a thickness defined by a top and a bottom thereof. The installation device can include a cylindrical body and an internal cavity. The cylindrical body can have a length greater than the thickness of the slab, where a first end is configured to be placed adjacent the top of the slab and a second end is configured to be placed below the bottom of the slab. The internal cavity can extend longitudinally through the cylindrical body from the first end of the cylindrical body to the second end of the cylindrical body, where the internal cavity has a first portion and a second portion. The first portion can have a first diameter located at the first end of the cylindrical body and the second portion can have a second diameter that is less than the first diameter. The internal cavity of the cylindrical body can be configured to receive the adaptor body therein.

A further aspect of the innovation includes where the installation device can include an adaptor body having a length, a proximal end, and a distal end. The adaptor body can also include a first barbed portion disposed at the proximal end of the adaptor body and a second barbed portion disposed at the distal end of the adaptor body. A collar portion can be disposed between the first barbed portion and the second barbed portion. And the adaptor body can have an internal cavity having an interior surface, where the internal cavity passes through the length of the adaptor body. The adaptor body can be disposed within the installation device. For example, the first barbed portion of the adaptor body can be located within the first portion of the internal cavity of the installation device and the second barbed portion of the adaptor body can be located within the second portion of the internal cavity of the installation device.

Methods of installing an installation device are provided where a rod can be placed into a sub-slab base material, the rod having a length greater than the cylindrical body of the installation device, and the rod configured to be disposed through the internal cavity of the cylindrical body. The cylindrical body of the installation device can be disposed about the rod, the rod can be disposed through the internal cavity of the cylindrical body, and the second end of the cylindrical body can be disposed into the sub-slab base material. The rod can then be removed from the sub-slab base material and the cylindrical body of the installation device.

Method of collecting a gas sample are provided that include drawing a gas sample through an adaptor body from a sub-slab base material. The adaptor body can be disposed within an installation device, the installation device can be disposed within a slab, and the slab can have a thickness defined by a top and a bottom thereof.

