This invention relates to a filtration apparatus for surface water, and more specifically to a filtration apparatus for removing sediment and other contaminants from surface water and adapted for insertion into existing curb inlet catch basins.
Surface water run-off is coming under increased scrutiny as a source of pollutants entering ground water, streams and rivers. As water from rain or snow melt and other sources flows over the surface of the ground it picks up a wide variety of pollutants, ranging from large and small debris, suspended solids and sediment to oils and other soluble and insoluble chemical contaminants. Because surface water is relatively easily contained through storm sewers and dry wells, many agencies at all levels of the government are paying increased attention to both the contaminants that enter the water system through surface water run-off, and to methods to control and eliminate such contaminants. Moreover, governmental regulations currently in place put restrictions on the amount of sediment that can be permitted to flow into sewer systems.
A municipal storm sewer system is one type of traditional surface water filtering system. In this type of system a series of catch basins or collection boxes are interconnected with sewer pipe. Surface water flows into the catch basin, often a relatively narrow un-grated inlet opening—the opening is often 4 inches or less in height. The water that flows into the opening enters the catch basin, which is a collection box or vault that functions essentially as a settling basin. Such collection boxes are sometimes called sump tanks. Some sediment that flows into the system settles to the bottom of the basin, and the water flows through an outlet pipe and into the sewer system and, depending upon the system, either to another processing facility or directly into a stream or river.
This traditional system is useful as a primary control system, and is relatively inexpensive, but it has many problems. As examples of the problems, the catch basin can quickly be filled with sediment if the water contains a high level of solids or sediment, causing the catch basin to become filled and the system to overflow or become clogged. Because the catch basin is typically a cylindrical tube or a rectangular box that sits below grade level, cleaning the sediment out of the basin can be a difficult job. Cleaning is made much more difficult if the system is clogged and the basin is underwater. Just as important, the system does not stop all of the sediment and other pollutants in the run-off. Typically, the water flow through the basin is fairly turbulent, especially when there is a lot of water flowing through the system, for instance during a storm. When this occurs very little sediment settles out, and is instead washed through the basin and into the sewer system. This may result in non-compliance with governmental regulations, possibly resulting in fines. Finally, a typical catch basin system does nothing to collect oils and other chemical contaminants and dissolved solids.
The grated catch basin type of system is routinely used with both private and municipal systems. In a dry well the surface water that flows through the sump tanks flows into a dry well associated with one or more basins rather than flowing into a municipal or other sewer system. However, to function properly, dry wells must have sufficient flow-through characteristics. Water containing a high level of sediment can quickly clog a dry well by stopping water flow-through. And as noted above, a grated catch basin does not stop oils and other chemicals. These kinds of pollutants, and especially oils that flow through the system can clog dry wells very quickly. Commercial dry wells can be very large, especially if they are used to contain run-off from a large area such as a large private parking lot, and are connected to numerous catch basins. It is typically very expensive to dig a new dry well, or to unclog an existing well.
As noted, many government agencies are paying increased attention to contaminants that are carried into streams and rivers in surface water run-off. Because polluted surface water run-off can be a significant source of pollution, agencies have begun to monitor the levels of contaminants in run-off, both in municipal and private systems. In the past several years, many municipalities have begun to impose fees on catch basin users, whether the catch basin is connected to a storm sewer system or a dry well. While these fees apply in most instances to commercial users, they can also apply to residential systems. In large part the fees are based in some manner on the kind and amount of pollutants that flow through the catch basin and into the system. In general, the higher the level of contaminants flowing through the system, the higher the fee. In some cases the amount of the fee is based on the kind of contaminant. For example, oils flowing into a sewer or dry well can lead to increased fees. These fees even apply to private commercial dry well users, since it is in the interest of a municipality to control the amount of pollution that enters the ground water.
There is therefore a strong incentive to decreasing both the amount and kind of contaminants flowing through a catch basin and into either a municipal sewer system or a private dry well or sewer system. First, there is an obvious environmental incentive: by decreasing contamination of all kinds from surface water run-off, the water that flows back into the ground and into streams and rivers is cleaner. This helps to improve environmental conditions in numerous ways. Second, there is a strong economic incentive: when sewer system and dry well users are paying fees based on the amount and kind of contaminants that flow into their systems, it is of obvious advantage to minimize all contaminants. Further, the costs associated with either cleaning catch basins or reconditioning dry wells are substantial. Avoiding or delaying those costs by reducing the amount of contaminants flowing through the system can save substantial amounts of money.
Curb-inlet catch basins are ubiquitous and are one type of vault used in storm sewer systems and functions the same as the systems described above. However, a curb-inlet catch basin is located along side roadways, typically those that are either paved with asphalt or which are concrete. Water flows off the roadway and enters the catch basin through an opening formed in a roadside curb. While there are numerous different designs for curb-inlet systems, a typical system has a below-grade vault made of reinforced concrete and which is connected to the sewer system through pipes. The vault is generally a square or rectangular box, the upper edge of which is typically at or near the same elevation as the roadway. A square riser or lid that is the same size as the vault and which also is typically concrete sits atop the vault. The riser is typically the height of the curb. A top unit typically sits atop the riser and defines a plate that rests on the riser and covers the vault. The top unit has a removable manhole cover, almost always round, which allows access to the vault for maintenance. Often, the lid is a one piece unit that covers the vault and has a manhole that provides access to the interior of the vault.
Curb-inlet systems present the same problems as the other systems described above and it is therefore desirable to filter water that flows into the systems. However, curb-inlet systems present unique challenges since the manhole access covers are typically round and the vaults beneath the covers are typically square and because the lid that covers the vault typically cannot be removed once it is in place, at least not without a significant amount of work involving equipment able to lift very heavy concrete structures (i.e., the lid). And in cases where the manhole access cover is other than round, the access plate to the underlying structures is typically smaller in size than the vault below the access plate. It is very difficult therefore to retrofit a filter system that easily fits through the round manhole cover and securely attaches to the vault. As a result, installation of conventional filtering systems is made very difficult; often the entire top unit has to be removed and a significant amount of labor is required to install the filter system.
There is a need therefore for a filter system that may be easily installed in existing curb-inlet catch basins.
The curb-inlet catch basin filtration system of the present invention is designed to be installed in existing curb-inlet catch basins that are in turn attached to existing municipal separate storm sewers and dry well systems and other storm water treatment systems, such as swales and infiltration ponds. The system of the present invention comprises a filter support plate that may be installed in a vault through the opening into the vault at the curb. Once the filter support plate is installed through the curb inlet, a filter system may be installed through the manhole. With the present system, the entire filter system may be installed in a vault without the need for workers to enter the vault. In other words, the workers need not climb into the vault at all; the entire system may be installed with workers remaining outside of the vault.
The filter support plate has a low profile that allows it to be inserted into the vault through the curb inlet. The plate is initially supported in the vault with one end resting on an interior ledge that is installed prior to insertion of the plate, and the other, street-side end suspended by a suspension bar. Adjustable jack bolts are attached to the support plate and secure the plate to the interior of the catch basin so that the platform is totally self-supported in the catch basin.
The support plate includes a retractable portion having an opening for suspending a primary and secondary filter system—the opening is positioned such that it lies directly below the manhole cover. Run-off flowing into the system preferably must pass through a flow path defined by the support plate and into filters as described herein. The inlet into the catch basin through the curb is a traditional inlet opening, which as noted is typically quite narrow in the height dimension, often 4 inches or less. Water flows onto the support plate and is directed into a primary filter, which is defined by a cylindrical perforate screen that has an open upper end and a perforate screen on the lower end; this filter traps solids that flow past the inlet opening. The screen is rigid or semi-rigid and optionally may be used to support an optional secondary filter. A cylindrical filter surrounds the perforate screen on the sides and bottom and the water passes through this secondary filter. The secondary filter comprises a non-woven sediment filter that optionally includes media contained in the filter. When media is incorporated into the secondary filter, the media selected for this secondary filter depends upon the conditions encountered at a specific location. The media may be specific to absorb oils and petrochemicals, as might be expected in run-off from parking lots. Similarly, oils are often contained in run-off from food processing facilities. Other types of media for removing other contaminants may also be used.
The portion of the support plate from which the primary and secondary filters are suspended is retractable both when the filters are installed and when the filters are removed. This allows access to the interior of the vault without removing either the primary or secondary filters. When the vault needs to be cleaned, the manhole cover is removed to allow workers to have access to the interior of the vault. The workers may either remove the primary and secondary filters or leave them in place if they do not require servicing. In either case, when the retractable portion of the support plate is retracted, the interior of the vault is exposed. A Vactor unit may then clean out the vault as usual before reinstalling the primary and secondary filters as the case may be. It will be appreciated that if the primary and secondary filters are removed, the workers will also have access to the interior of the vault through the opening in which the filters are suspended, even without retracting the support plate.
The invention will be better understood and its numerous objects and advantages will be apparent by reference to the following detailed description of the invention when taken in conjunction with the following drawings.
The invention will now be described in detail with reference to the drawings. It will be understood that relative directional terms are used at times to describe components of the invention and relative positions of the components. As a naming convention, the plane of the ground, for example, in
The difference between
As shown in several of the figures and perhaps best shown in the cross sectional view of
The inlet 104 into the vault 100 is typically a fairly restricted opening—a dimension of 4 inches in height by 48 inches in width is typical although there is no “standard” inlet opening dimension and there are a wide variety of inlet opening dimensions used. In any case, for purposes herein, the height dimension of the un-grated inlet opening 104 is defined as X and the width dimension is Y as illustrated in
Reference is now made to
Also visible in
With reference to
As best illustrated in
Cap 302 is removed to allow access to the interior of vault 100 as shown with arrow A in
As noted, second support plate 16 is movable from a first position in which edge 13 of the plate 16 is pushed up against wall 32 as shown in
With returning reference to
Returning again to
Apparatus 10 includes a mechanism that facilitates support of the end of plate 11 that abuts interior wall 50 of the vault 100—that is, edge 15—during the installation process. As noted previously, prior to insertion of the apparatus 10 into the vault interior 110 through the opening 104, a support plate 30 is attached to interior wall 32. When the apparatus 10 is initially inserted into the vault, ends 60 and 62 of jack bolts 20, 22, rest on the support plate 30 to thereby support edge 13 of plate 11 adjacent wall 32 during installation. As seen in
The primary and secondary filter assemblies used in apparatus 10 and how they are suspended by plate 16, through opening 18, are illustrated in several figures, notably
With reference to
Filter assembly 500 is defined by a cylindrical mesh strainer basket 502, which defines the primary filter, and a secondary filter 504 (detailed below and shown in, for example,
Strainer basket 502 is preferably cylindrical but can be of any shape and the size of the perforate openings in the mesh can be varied to accommodate conditions at any given site where the inventive apparatus described herein is located. As an example, if the site has a relatively large amount of small solid objects such as small rocks flowing into the system, a strainer basket 502 having perforate openings of an appropriate size can be selected and used. To facilitate easy removal of strainer basket 502 from its position in plate 16, a handle 508 is provided. Because the strainer basket of the preferred embodiment is cylindrical it has substantial surface area to volume ratio and thus has substantial filtering capacity. It can thus be used to filter out a substantial amount of debris before it becomes full or clogged. As particulate matter accumulates within the strainer the basket fills from the bottom toward the top. Water is still able to flow freely through the filter sides until it is completely full.
With reference now to
A strip of flexible sealing strip 72 is optionally extended around the periphery of support plate 11, or portions of it, so that it seals against the adjacent interior walls of the vault. For example, a sealing strip 72 is shown in
Installation of apparatus 10 into a vault 100 will now be described in detail. As noted previously, support plate 11 has a low profile that allows it to be inserted through inlet opening 104, which as noted may be as small as 4 inches by 48 inches. The height dimension of the support plate 11 is less than the height dimension of the inlet 104. As such, the apparatus may be installed in existing vaults that have already been placed in the ground and there is no need for workers to actually enter the vault. The installation process requires as a first step that the support plate 30 is attached to the rear interior wall 32 of vault 100. The support plate 30 may be a length of angle iron that is bolted to the wall 32 and preferably includes slotted bolt holes 29 that allow the plate to be adjustable to make sure that it is level (i.e., with slotted bolt holes defined by vertical channels 29 in the plate). The width of support plate 30 is greater than the width between jack bolts 20 and 22. The support plate 30 may be installed by workers reaching into the vault through the manhole opening 108.
With support plate 30 in place, the support plate 11 is inserted through inlet 104 with edge 13 being inserted first; edge 13 defines the leading edge in the installation process and edge 15 thus defines the trailing edge. The plate is inserted in the orientation shown in
In this position, with the support plate initially located in the interior of the vault, the proximal ends 40, 42 of jack bolts 20 and 22 lie close to the interior wall 50 of vault 100. The plate 110 is adjusted so that it is level and edge 54 is tight against the edge 56 of the vault (and seal 72 is sealed against the wall), and the jack bolts 20 and 22 are tightened. This drives the jack bolts to extend them longitudinally, driving the distal ends 60, 62 into wall 32 and the proximal ends 40, 42 into wall 50, thereby securing the plate tightly in the vault.
Plate 70 defines a lateral width adjustment plate that defines the means for adjusting the width of plate 12 to the desired width. Plate 70 is adjustably attached to first plate section 12 so that the plate 70 may be slid laterally in the directions of arrow C in
The plate 70 is adjusted in its position in vault 100 so that water flows onto the plate 14 across the entire width of opening 104. Water flowing onto plate 14 flows directly into opening 18. As such, it may be desired to angle the support plate 11 at a slight downward angle relative to the ground plane and toward opening 18—this defines a downwardly sloping flow path from the edge 15 of the plate toward edge 13 toward the back wall 32 of the vault.
As noted previously, the apparatus may be installed in an existing vault without the need for workers to ever enter the vault itself; all work may be done from the outside of the vault. This is a significant improvement in ease of work, efficiency and safety for the workers.
It will be appreciated that the present invention not only allows for installation without workers entering the vault, but also allows the vault to be cleaned without workers entering the vault. Specifically, to clean the vault the filter basket 502 and secondary filter 504 are removed by lifting them upwardly through the manhole opening 108. The retractable second plate section 16 is then moved into its retracted position (i.e., the position in
The invention allows workers using a Vactor truck, a jetter truck, a camera truck and similar equipment to maintain and inspect the interior of the vault without having to remove the filter device and without requiring personnel to enter the confined space of the vault; all necessary installation, servicing and inspection may be done from outside the vault. The device has a primary and secondary filtration system and a testing port 300 which will allow testing of incoming water, and all work may be done by simply removing the manhole cover.
While the present invention has been described in terms of a preferred embodiment, it will be appreciated by one of ordinary skill that the spirit and scope of the invention is not limited to those embodiments, but extend to the various modifications and equivalents as defined in the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
5232587 | Hegemier | Aug 1993 | A |
5405539 | Schneider | Apr 1995 | A |
5643445 | Billias | Jul 1997 | A |
6254770 | Remon | Jul 2001 | B1 |
6884343 | Harris | Apr 2005 | B2 |
7670483 | Ringenbach | Mar 2010 | B2 |
8343357 | Horner | Jan 2013 | B2 |
8608956 | Moulton | Dec 2013 | B2 |
20050183997 | Happel | Aug 2005 | A1 |
20110155672 | McInnis | Jun 2011 | A1 |
Number | Date | Country | |
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20140238915 A1 | Aug 2014 | US |
Number | Date | Country | |
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61767926 | Feb 2013 | US |