Water pollution trap with clay collector

A chamber having an inlet for receiving polluted storm-water runoff and an outlet for the storm water to flow out. Within the chamber is a pivotal filter that catches clay during typical storm flows and pivots out of the way during higher flows. In alternative embodiments, there are included a screen, one or more baffles, and/or a collection reservoir for further dispersing, detaining, and/or filtering the storm water.

TECHNICAL FIELD

The present invention relates generally to water pollution traps and, more particularly, to oil/grit separators for separating and collecting various pollutants from storm-water runoff.

BACKGROUND OF THE INVENTION

During rainstorms, water that is not absorbed into the ground runs off into storm sewer systems for delivery into freshwater systems such as streams, rivers, lakes, and wetlands. While flowing across parking lots, landscaped areas, and other surfaces, the storm-water runoff picks up debris and pollutants and carries them into the storm sewer systems. Particularly large amounts of pollutants are picked up at shopping centers with large parking lots, oil-change and auto-repair shops, gas stations, and so forth. These pollutants include motor oil and other hydrocarbons, particulate matter such as sand and grit, and miscellaneous debris such as vegetative matter, paper, plastic, and foam cups. For example, about 200 pounds of miscellaneous debris and 500 pounds of sand and grit is commonly carried off by storm-water runoff from some one-acre parking lots in 90 days.

To maintain freshwater systems, most cities and counties have regulations requiring that some of the pollutants be removed from the storm-water runoff before entering their storm sewer systems. In order to meet these regulations, facilities typically install on-site pollution traps to filter the storm-water runoff. These pollution traps are sometimes referred to as “oil/grit separators.”

Most conventional pollution traps provide only “first flush” filtration during the typical local storm event, but permit bypassing the filtration stage for larger storms. In fact, many jurisdictions require bypassing, some even at typical storm water flows. Bypassing filtration is a problem because most pollutants are more easily picked up and transported by storm water during higher flow periods. Unfortunately, just when the traps are needed most, a lot of pollutants bypass them and are delivered into the storm sewer systems. And most pollution traps that do not provide for bypassing accommodate the larger flows because they are oversized, which adds significantly to the cost to build, install, and maintain them.

Another problem with many pollution traps is they simply filter the storm water at the natural flow rate of the storm water passing through it. The faster the storm water flows through the trap, the less particulate matter pollutants can settle in the trap. Some other traps detain the storm water for a brief time to allow some of the particulate matter to settle. But these traps only detain the water for a few minutes at most, and even a small water flow will cause the particles to be re-suspended in the water. Therefore, these pollution traps allow a lot of particulate matter pollutants to pass though them, even before bypass occurs.

In addition, the filtering systems of some pollution traps include screens for capturing miscellaneous debris. These screens are typically partially submerged in the water in the middle of the trap so that the debris is always floating in the water. Because the debris is always floating, it does not block the screen. The problem with this configuration is that vegetation, paper, and other absorbent miscellaneous debris tends to become waterlogged, rot, and deteriorate into smaller parts. These small parts then pass through the screen, are re-suspended in the water, and are carried out of the trap. Moreover, vegetative matter contains nitrogen and phosphorus and carries other pollutants such as fertilizer, pesticides, and oils. And paper products carry inks and other surface adherents. So now these additional pollutants also pass through the screen with the deteriorated debris and out of the trap.

In general, typical known pollution traps are designed for a typical water flow. Often the pollution traps are ill-suited to operating effectively over a widely differing range of water flows. Indeed, sometimes greater than typical storms can overwhelm known pollution traps.

Accordingly, it can be seen that a need remains for a pollution trap that stays on-line and filters all the storm-water runoff from a parcel of land, without bypassing filtration or overflowing during larger-than-typical storms. In addition, there is needed a pollution trap that is effective for removing particulate matter from the storm water and is still somewhat effective even when the flow is well above that of a typical storm. Furthermore, a need exists for such a pollution trap that is cost-efficient to build, install, and maintain. It is to the provision of a pollution trap meeting these and other needs that the present invention is primarily directed.

SUMMARY OF THE INVENTION

The present invention provides an innovative trap for separating pollutants from storm water runoff. The trap separates pollutants such as miscellaneous debris including vegetative matter, plastic, and paper, particulate matter including sand, grit, and clay, and/or floating matter including motor oil, other hydrocarbons, and detergents. In addition, the trap can be used to separate other pollutants from other liquids, as may be desired in a particular application.

Generally described, the water pollution trap includes a chamber and a pivotal filter positioned between an inlet and an outlet of the chamber. The chamber has a floor, a worst storm water level when the water is flowing through the chamber at a maximum water flow rate, and an at-rest water level when none of the water is flowing into the chamber. The pivotal filter is configured to filter out at least some of the clay or other pollutants.

In an exemplary embodiment of the present invention, the pivotal filter is constructed of a rigid frame holding a removable fibrous filtration member. The fibrous filtration member may be made of, for example, coconut fiber or another material for filtering clay or other particulate matter.

The pivotal filter pivots from a filtering position when a typical flow of the water is flowing through it toward a bypass position in response to a larger-than-typical flow of the water pushing against it. In this way, the pivotal filter stays in the filtering position during typical storms or between storms. But during larger-than-typical storms, the upward force of the water against the pivotal filter pushes it out of the way so that it does not impede the flow of the water out of the chamber.

In addition, the pivotal filter can be used in combination with other filtration stages positioned in the chamber, including a screen, one or more baffles, and/or a collection reservoir with a skimming edge. The screen is configured to suspend at least some of the miscellaneous debris or other pollutants above the at-rest liquid level. The baffles are configured to increase water residence time in the chamber to encourage settling of the particulate matter or other pollutants. And the collection reservoir is configured to skim at least some of the floating matter or other pollutants into it.

The screen is positioned at or above the at-rest water level so that the screen retains some of the pollutants, allows the water to pass through it, and suspends the retained pollutants above the at-rest water level. In this way, the suspended retained pollutants are kept dry when there is no storm so that they do not waterlog, deteriorate, and pass through the screen. The screen can be, for example, basket-shaped but with an open side adjacent the inlet.

The baffles are each configured and positioned in the chamber to form at least one gap through which the water may flow around the baffle. In this way, the water flows around the baffles in a longer flow route through the chamber, without flowing any faster. Preferably, the collective flow area through the baffles is significantly greater than the flow area of the inlet to cause the linear speed of the flow to slow substantially while maintaining the volume of the flow constant. This increases the residence time of the water in the chamber, which encourages settling of some of the pollutants.

In addition, the baffles may have apertures in them that permit at least some of the liquid to pass through them. In this way, the apertured baffles disperse the water, which further encourages settling of some of the pollutants.

The collection reservoir has a skimming edge that is positioned at or adjacent the worst storm water level to skim floating pollutant matter into the collection reservoir. As the water flow through the chamber increases during larger-than-typical storms, the floating pollutants rise with the water level until they are skimmed off the surface of the water and into the reservoir, instead of bypassing the trap. In order to provide for adjusting the skimming edge for the maximum water flow at a particular installation, the skimming edge may be provided on a weir member that is vertically adjustable and mounted to a front wall of the collection reservoir.

In addition, the bottom of the collection reservoir may be positioned above the chamber floor to permit the water to flow under the collection reservoir. In this way, the water flow route through the chamber is increased to further encourage settling of some of the pollutants.

In this exemplary combination embodiment, the screen, baffle, reservoir, and pivotal filter filtration stages cooperate to provide a significant increase in performance over conventional pollution traps. In particular, the screen suspends at least some of the miscellaneous debris above the at-rest water level, the baffles increase water residence time in the chamber to encourage settling of the particulate matter, the collection reservoir skims at least some of the floating matter into it but allows the water to flow under it, and the pivotal filter filters out at least some of the suspended clay. It will be understood by those skilled in the art that these filtration stages can be used in this or other configurations for separating other pollutants from other liquids.

Accordingly, the pollution trap stays on-line and routes all the storm-water runoff through it, instead of bypassing or overflowing during larger-than-typical storms. In particular, the pollution trap pivotal filter catches clay during typical storm flows and pivots out of the way without causing the trap to overflow during higher flows. Additionally, when the pivotal filter is used in combination with the screen, baffles, and collection reservoir, the pollution trap induces settling of particulate matter, reduces waterlogging of absorbent miscellaneous debris, and collects floating hydrocarbons during larger-than-typical storms when more of these pollutants are carried by the storm water, thereby providing improved filtration of pollutants from the storm water. Furthermore, the pollution trap is cost-efficient to build, install, and maintain.

These and other features and advantages of the present invention will become more apparent upon reading the following description in conjunction with the accompanying drawing figures.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Referring now to the drawing figures, wherein like reference numerals represent like parts throughout the several views, the pollution trap of the present invention provides for separating pollutants from storm-water runoff and retaining the pollutants in the trap or a nearby storage container. The pollution trap is well suited for filtering pollutants including floatable matter such as motor oil, other hydrocarbons, and detergents, particulate matter such as sand, dirt, and grit, and miscellaneous debris such as vegetative matter from trees, shrubberies, etc., paper and plastic trash, aluminum foil wrappers, foam cups, and so forth. In addition, a person of ordinary skill in the art could adapt the pollution trap described herein in order to separate other types of pollution or other types of matter from liquids other than storm water, if so desired.

The pollution trap of the present invention includes a pivotal filter for separating clay and other pollutants from the storm-water runoff. The pollution trap may additionally include a screen, baffles, and/or a collection reservoir. For illustration purposes, the trap will be described herein including the pivotal filter and these other filtration stages. It will be understood, however, that the trap can be provided with only the pivotal filter or with the pivotal filter in combination with these and/or other filtration stages selected to provide the pollutant separation desired in a particular application.

FIGS. 1-2show a first exemplary embodiment of the present invention, referred to generally as the pollution trap10. The pollution trap10includes a chamber12that houses the screen100, the baffles200, the collection reservoir300, and the pivotal filter400. In a typical commercial embodiment, the screen100is positioned adjacent an inlet to the chamber12, the baffles200are positioned between the screen and an outlet to the chamber, the collection reservoir300is positioned between the baffles and the outlet, and the pivotal filter400is positioned between the collection reservoir and the outlet. It will be understood that, while in the exemplary embodiment the pollution trap10includes all four of these filtration stages100-400, in alternative embodiments such as those described below the present invention can be provided with only one of these stages or with various configurations and combinations of them in various other positions.

In the first exemplary embodiment, the chamber12is rectangular and is formed by end walls14and16, sidewalls18and20, a floor22, and a lid24. The chamber end walls14and16, side walls18and20, and floor22are made of reinforced concrete, and may be sealed with a coating such as a bituminous material for making the chamber watertight. The concrete chamber12is pre-cast and hauled to the installation location, though it could be cast on-site if so desired.

For convenience in constructing, hauling, and installing the chamber12, it can be formed into two or more sections. For example, a base section13can be made with a standard size, and one or more riser sections15can be made in a variety of heights or custom-made per job. In this way, the height of the riser section15is selected so that the lid24will be at about ground level given the depth at which the base section13will be installed. In installations where the top of the base section13is at grade, no riser section15would be used. Alternatively, the chamber12can be integrally made as a single piece.

The lid24covers the open top of the chamber12, and can be at least partially removable in order to provide ready access to the inside of the chamber for maintenance of the trap10. For example, the lid24can be made of three steel panels, with a fixed middle panel and two end panels pivotally coupled to the middle one. Alternatively, the lid24can be made of concrete and include a steel manhole ring and cover. In addition, when the lid24and the chamber walls14,16,18, and20are installed in areas where they are driven over, they can be sized and/or reinforced to withstand the traffic loadings they are subjected to.

Of course, the lid24and the chamber walls14,16,18, and20can be made in other regular or irregular shapes and configurations, and can be made of other strong and durable materials, as may be desirable in a given application. For example, the chamber walls14,16,18, and20could be made of fiberglass, hard plastic, or a composite, and/or the chamber12could be generally L-shaped or triangular with two inlets and one outlet.

Additionally, the chamber12has an inlet opening26in one of the end walls14through which the water flows into the chamber and an outlet opening28in the other end wall16through which the water flows out. The inlet26and the outlet28are sized and shaped to receive or otherwise connect to the pipes27of conventional storm sewer systems. If desired, the inlet26and the outlet28can include stub-outs for connecting to the conventional storm sewer pipes27. The stub-outs can be provided by, for example, sections of metal or PVC pipe.

The inlet26and the outlet28are sized to handle a predetermined maximum flow rate based on the tributary area to be drained and the worst storm event the trap is intended to handle. For example, the maximum flow rate can be based on the 25-year storm (the worst storm over a 25-year period for the geographic location, on average), or for an otherwise-defined catastrophic or larger-than-normal storm. Of course, during most storms, the inlet26and the outlet28do not see anywhere close to the water flow intensity of the 25-year storm.

Furthermore, a worst storm (maximum) water level30is defined in the chamber12when the water is flowing through the chamber at the maximum water flow rate, and an at-rest water level32when no water is flowing into it. More particularly, the at-rest water level32at its highest is at the bottom of the outlet28, because the water cannot flow out of the chamber12when it is at this level. And, of course, the worst storm water level30is higher than the at-rest water level32. Moreover, because the worst storm water level30is defined by the water level during the worst storm event, it is determined at least in part by the size of the inlet26, the outlet28, and the chamber12.

In a typical commercial embodiment, the chamber is 11 feet high (6 foot base plus 5 foot riser), 5 feet wide, and 10 feet long, with 6 inch thick walls. And the inlet and the outlet are 15 inch openings positioned about 4 feet above the chamber floor, with the bottom of the outlet positioned about 0.1 foot lower than the bottom of the inlet. With these dimensions, the trap can successfully handle (without overflowing or bypassing) about 9.2 cubic feet per second (cfs), which is greater than the volume flow rate for the 25-year storm for a typical installation with a 1 acre tributary area. At this flow rate, the vertical exit velocity is about one foot per second, which is slow enough to retain particles larger than 20 microns in the pollution trap. For comparison, many conventional traps bypass at only 1 to 2 cfs, which often occurs during a typical “first flush” storm event.

It will be understood that many variations of these dimensions may be used, depending on the size, grade, ground covering, and use of the tributary area to be drained, the typical and maximum rainfall during the design worst storm event, the local restrictions on flow rates, any physical space limitations for the pollution trap, and so forth. For example, in some other embodiments, the inlet and the outlet are provided by 18 or 24 inch openings for handling greater maximum flow rates, and the chamber riser section is only 2 or 3 feet high where the base section is installed closer to grade.

To put it more succinctly, the inlet26and the outlet28are designed to handle the predetermined maximum flow rate of storm water for a maximum design storm event, for example, the 25-year storm. This typically means matching the inlet26and the outlet28to the size of the storm sewer pipe, whether preexisting or new. If the storm sewer pipe is under pressure, then the inlet26may be sized larger to slow down the water flow as it enters the chamber12. And the outlet28may be the same size as the inlet26or larger. In any event, the chamber12is designed so that all of the water that can be delivered into it from the inlet26can pass through it and out of the outlet28. Finally, the filter stages100,200,300, and400are configured so that they permit passing through the chamber12of the maximum water flow during the maximum design storm event, so the reservoir300does not overflow and the trap10does not need to be bypassed.

Referring now toFIGS. 1-4, the screen100catches most to all of the floating miscellaneous debris such as vegetative matter, plastic, and paper that might otherwise collect in the chamber12and/or be washed over into the reservoir300. To filter the storm-water as it enters the chamber12, the screen100is positioned adjacent the inlet26and flush against the end wall14. Also, the screen100is vertically positioned at or just above the at-rest water level32, and thus at or just below the bottom of the inlet26.

In this position, during a storm the screen100collects and retains the debris as it enters the chamber12, allows the water to pass through it, and suspends the retained debris above the at-rest water level32. After the storm, the water level drops down to the at-rest water level32, so the debris is suspended in the air and can now dry out. In this way, the suspended debris does not become waterlogged, break down into smaller pieces, and wash through the screen100. And the nitrogen, phosphorus, fertilizer, pesticides, oils, inks, surface adherents, and other pollutants contained in or carried by vegetative matter and paper also remain trapped by the screen100. The result is a significant increase in the amount of debris and other pollutants retained over time by the screen100relative to conventional traps.

In addition, as the debris builds up on the screen100over time, it tends to mat together, particularly the leaves and other vegetative matter. This matted debris then creates a natural filter on the screen100that provides additional levels of filtration. The way it works is the matted debris begins to stop larger gravel and sand particles. These particles fill the spaces in the matted debris and, in a “beaver dam” effect, cause smaller particles to be trapped. The result is that very fine particles, pollen, mud, sand, etc., are collected in the built-up layers of the matted debris on the screen100. And these particles are often retained there because the water flow through the trap10is normally not very great. That is, typical storms often produce a water flow only few inches deep through the inlet26, very often amounting to barely a trickle. So the particles trapped by the matted debris are often retained there and not washed away through the screen100.

Furthermore, the screen100preferably extends all the way across the chamber12. That is, the ends of the screen are adjacent the sidewalls18and20of the chamber. With the screen100being long relative to the diameter of the inlet26, as the storm-water enters the chamber12it is free to disperse laterally. The dispersing and screening of the water by the screen100tends to break up any organized eddies and vortices. This encourages settling of the particulate matter pollution within the chamber12.

Turning now to the construction of the screen100, in a typical commercial embodiment it is basket-shaped but with an open side101that is adjacent the inlet26for allowing the debris into the chamber12. The generally basket-shaped screen100is provided by a rigid frame102that holds a liner104. The frame102is made of aluminum grating and has a bottom106, a side108, and ends110. The liner104is made of aluminum ¼ inch mesh and has a bottom112, a side114, and ends116. Accordingly, the frame bottom106and the liner bottom112are positioned at or above the at-rest water level32.

For ease of removing the trapped debris and particles from the screen100, it is provided with handles118and removably mounted in the chamber12. For example, the screen100can be supported on mounting structures120such as mounting brackets, pins, bolts, or other mounting structures. The mounting structures120support the screen100and restrain it from lateral or downward movement, but permit removal of the screen by lifting it from the brackets. Thus, the screen100does not have to be decoupled from the mounting structures120for its removal from the chamber12.

Alternatively, the screen100can be made in other shapes, sizes, and materials, and be positioned elsewhere in the chamber12. For example, the liner can be made of 1/16 or ⅛ inch mesh, perforated panels, lattice structures, or other structures with filtering spaces, made of stainless steel, plastic, a composite, or another material, and constructed without ends and/or extending only part of the way across the chamber. Or the liner can be eliminated and the screen provided with the smallest desired filtering spaces in the frame instead of in the liner. And the frame can be provided a structure other than grating but still having openings in it, made of stainless steel or another suitable material, and constructed without the ends and/or extending only part of the way across the chamber.

FIGS. 5A-5Cdepict several alternative embodiments of the screen. In a first alternative embodiment shown inFIG. 5A, the screen100ahas a bottom106aand a side108a, and additionally includes a top122a. In a second alternative embodiment shown inFIG. 5B, the screen100bhas a bottom106bthat is angled. And in a third alternative embodiment shown inFIG. 5C, the screen100chas a bottom106cthat is curved. These embodiments can be provided with or without ends, which are not shown in the respective drawings. It will be understood that the screen can be provided in alternatively-configured embodiments not described herein but that provide the same above-described advantages.

Referring now toFIGS. 1,2and6, each one of the baffles200is configured and positioned in the chamber12to form at least one gap202through which the water can flow to get around the baffle. So instead of the water naturally flowing straight through the chamber12, it is diverted around the baffles200through the gaps202. The diverted flow of the water around the baffles200results in a longer flow route through the chamber12. Also, the water flows past the baffles200no faster than when it entered the chamber12, as described in detail below. Because the water travels the longer route around the baffles202but is not throttled, the water resides in the chamber12for a longer time. This increased water residence time encourages the particulate matter carried by the water to settle to the floor22of the chamber12.

The position, configuration, and number of the baffles200and the gaps202formed by them are selected depending on the water residence time desired for a particular installation. For example, in the presently described embodiment, two baffles200′ and200″ are provided. The first baffle200′ has a bottom204′ positioned at the chamber floor22and a top206′ positioned below the worst storm water level30. In this position, a top gap202′ is formed between the baffle top204′ and the worst storm water level30to encourage the water to flow over the baffle200′. The baffle top204′ may be positioned at the at-rest water level32so that the water begins flowing over it at the outset of storm water flowing into the chamber12. Or the baffle top204′ may be positioned higher, closer to the worst storm water level30, so that the water only begins flowing over it sometime after the storm has begun or only during larger storms.

The second baffle200″, which is shown inFIG. 6, has a bottom204″ that is positioned above the chamber floor22and a top206″ that is positioned at or above the worst storm water level30. In this position, a bottom gap202″ is formed between the baffle bottom204″ and the chamber floor22to encourage the water to flow under the baffle200″. But the water cannot flow over the baffle top206″, at least not during typical storms or larger-than-typical storms up to the worst storm event.

In addition, the first baffle200′ has sides208′ and the second baffle200″ has sides208″, with the sides208′ and208″ preferably extending substantially all the way across the chamber12. That is, the baffle sides208′ and208″ are positioned at the sidewalls18and20of the chamber12. In this position, the water can not flow around the baffle sides208′ and208″, but instead is forced to flow up over the first baffle top206′ through the gap202′ and then down under the second baffle bottom204″ through the gap202″. Thus up-and-down water flow produces the longer flow route and increased residence time of the water in the chamber12.

As used herein, the second baffle top being positioned “at” the worst storm water level is intended to include being positioned adjacent to but just below the worst storm water level. And the first baffle bottom being positioned “at” the chamber floor is intended to include being positioned adjacent to but just above or recessed down into the chamber floor. Also, the sides of the baffles being positioned “at” the chamber sidewalls is intended to include being positioned adjacent to but spaced slightly from or recessed into the chamber sidewalls.

Furthermore, one or both of the baffles200may be provided with apertures210in them. The apertures210permit some of the water and the pollutants carried by it to pass through the baffles200. When some of the water flows through the apertures210while the rest of the water is impeded by the baffles200, the water flow tends to disperse and break up any organized eddies and vortices. As with the screen100, this encourages settling of the particulate matter in the chamber12.

Also, some of the oil and/or other floating matter may be forced below the water surface upon entering the chamber12, and the water flow dispersal provides some time for it to rise back to the water surface. In addition, the apertures210permit the floating matter to pass through them. Accordingly, the first baffle200′ has the apertures210along all or much of its height, with lower apertures for permitting the temporarily submerged floating matter through and upper apertures for permitting the remaining floating matter through. Similarly, the second baffle200″ has apertures210in its upper portion212for permitting the floating matter through. But to encourage the water to flow down through the lower gap202″, and because by now most to all of the floating matter has returned to the water surface, the lower portion212of the second baffle200″ need not have any apertures210.

As mentioned above, the water flows past the baffles200no faster than when it entered the chamber12. This is because for each of the baffles200′ and200″, the combined cross-sectional area of the gap around it and the apertures in it is larger than or equal to the cross-sectional area of the inlet26. For example, in a typical commercial embodiment, the cumulative area of the baffle gap and apertures is three to five times greater than the inlet area. In this way, the water flows freely into the chamber12at the inlet26and is not throttled as it passes around the baffles200. Instead, the water slows down in the chamber12, or at least is allowed to continue no faster than its inlet flow rate, to encourage the particulate matter to settle.

Turning now to the construction of the baffles200, in a typical commercial embodiment they are provided by panels that are generally flat and made of aluminum, stainless steel or another metal. The width of each of the gaps in the panels is at least about 3 inches. The diameter of the apertures is 1 inch, arranged in an array on 1¼ centers. The lower portion of the panel with no apertures is about 15″ high. The panels are mounted in the chamber by conventional mounting structures such as mounting brackets, pins, bolts, or other mounting structures. In this configuration, the water flow rate through the trap is kept under about 1.0 feet per second even during the maximum storm event, which is slow enough to enable the trap to collection about 2 inches of particulate matter in typical installations.

Alternatively, the baffles may be provided by panels that are curved, zigzagged, corrugated, L-shaped, have a combination of these profiles or shapes, or are otherwise configured. Also, the baffles may be made of fiberglass, plastic, a composite, or another material. The size, number, and position of the gaps and the apertures may vary and be selected to provide the water flow dispersion, route, and rate desired for a particular installation. Accordingly, sometimes only one baffle is provided, and other times more than two are used. In some installations, each or particular ones of the baffles have gaps formed at both the top and the bottom, at one or both sides, all the way around them, and/or at intervals in a serrated or scalloped configuration, or otherwise. In addition, the apertures may be arranged in an array with a regular pattern or an irregular arrangement. And some of the apertures may be larger than other ones. Furthermore, the baffles may be configured and positioned primarily for dispersing the water, primarily for lengthening the flow route through the chamber, or both.

FIGS. 7A-7Fdepict several alternative embodiments of the baffles.FIGS. 7A and 7Bare elevation views showing alternative top and/or bottom baffle gap configurations, whileFIGS. 7C-7Dare plan views showing side gap configurations.

In a first alternative embodiment of the baffles shown inFIG. 7A, the first baffle200a′ is coupled to the screen100so that it does not need to be mounted to the chamber12. Also, the first baffle200a′ has bottom gap202a′ so that the water flows under it, and the second baffle200a″ has top gap202a″ so that the water then flows back up over it.

In a second alternative embodiment shown inFIG. 7B, the first baffle200b′ has both bottom and top gaps202b′ so that the water flows both under and over it. And the second baffle202b″ has an intermediate gap202b″ between its top and bottom, for example, along its horizontal centerline, through which the water flows. In this configuration, the gap202b″ may be provided by a slot in the second baffle or two separate panels may be provided to form the second baffle.

In a third alternative embodiment shown inFIG. 7C, only one baffle200cis provided, and it has side gaps202cformed vertically at its sides208c. In this configuration, the water is diverted around the sides208cof the baffle200c.

In a fourth alternative embodiment shown inFIG. 7D, the first baffle200d′ and a third baffle200d′″ have side gaps202d′ and202d′″, and the second baffle202d″ has an intermediate gap202d″. In this configuration, the water flows around the sides of the first baffle200d′ through the first gaps202d′, inward toward the center of the chamber12, through the intermediate gap202d″ between the sides of the second baffle200d″, back outward toward the sides of the chamber12, and around the sides of the third baffle200d′″ through the third gap202d′″.

In a fifth alternative embodiment shown inFIG. 7E, the first baffle200e′ and the second baffle202e″ are generally L-shaped and opposing each other to form side gaps202e′ and202e″ and an intermediate channel216e. In this configuration, the water flows around one side of the first baffle200e′ through the first gap202e′, reverses direction and flows back toward the first baffle through the intermediate channel216e, then reverses direction again and flows through the second gap202e″.

In a sixth alternative embodiment shown inFIG. 7F, the first baffle200f′ has top corner gaps202f′ and the second baffle202f″ has a bottom intermediate gap202f″. In this configuration, the water flows upward and laterally to the sides of the chamber12, over the first baffle200f′ through the top corner gaps202f′, back downward and toward the center of the chamber12, and under the second baffle200f″ through the bottom intermediate gap202f″. It will be understood by those skilled in the art that other configurations, positions, numbers, and sizes of the baffles can be provided to accomplish the above-stated functions of dispersing the water flow and increasing the water residence time.

Referring now toFIGS. 1,2,8, and9, the collection reservoir300has a front wall302and a skimming edge304positioned at the worst storm water level30, or at a selected storm water level for a lesser storm event to allow oil collection at that selected level. The skimming edge304skims into the reservoir300at least some of the oil and/or other pollution floating on the surface of the water. And at least the portion of the front wall302below the at-rest water level32extends all the way across the chamber12, so the water cannot flow around the sides of the reservoir300. So instead of the floating matter flowing through and out of the chamber12on the water surface, it is skimmed into the reservoir300and thereby segregated from the water.

In addition, the collection reservoir300divides the chamber12into a front sub-chamber46and a rear sub-chamber48. The sub-chambers46and48provide pools with sufficient depths to encourage settling of the particulate matter, and are in fluid communication through a gap47. The rear sub-chamber48has a cross-sectional area larger than that of the inlet so that the water flows slower through it. In this way, the particulate matter flows under the collection reservoir300through the reservoir gap47, then back up through the rear sub-chamber48and out of the chamber12through the outlet28. Because of this longer flow route, because the water is flowing slower, and because of the gravitational forces on the particulate matter as the water decelerates up through the rear sub-chamber48to get out of the chamber12, more of the particulate matter settles to the chamber floor22instead of flowing out of the trap10.

The reservoir gap47is defined by a bottom wall306of the collection reservoir300, the floor22of the chamber12, and the chamber sidewalls18and20, to allow the water to flow under the reservoir. In order to keep the water from flowing any faster than when it entered the chamber12, the cross-sectional area of the reservoir gap47is the same as or larger than the cross-sectional area of the inlet26. Preferably, the water is slowed by sizing the reservoir gap47larger than the area of the inlet26, for example, by a factor of about three to five. By keeping the flow rate relatively slow, more of the particulate matter will settle in the chamber12.

In the first exemplary embodiment, the collection reservoir300is formed by the front wall302, a rear wall308, sidewalls310, and the bottom wall306extending between them. For standardized traps, the skimming edge304can be defined on the front wall302or another component of the reservoir300. To provide for adjustability for site-specific conditions, however, the skimming edge304can be defined by the top of a weir member312that is adjustably mounted to the front wall302or another part of the reservoir300.

The weir312is preferably adjustably mounted to the front wall302by bolt-and-slot assemblies314. Alternatively, another suitable mounting may be used instead. For example, the front wall and the weir may be provided with a series of holes that can be selectively aligned for receiving a bolt (with unused holes plugged), or the weir can slide on a track, in a channel, or otherwise.

In addition, the front wall302has an opening316in it, and the weir312is vertically adjustable to cover all or some of the opening. The opening316is formed between two side tabs318of the front wall312, and the weir overlaps with and is adjustably mounted314to the side tabs.

Also, the collection reservoir300may be provided with a maintenance opening and removable plug assembly320positioned below the skimming edge304. For example, the opening and plug assembly320may be provided in the front wall302and/or in the weir member304. For installations that process substantial amounts of floating matter, a thick blanket of it builds up during typical storms because the water level does not get high enough for it to be skimmed into the reservoir. During maintenance visits, the plug can be removed to drain the blanket of floating matter into the reservoir300.

After the floating matter has been skimmed or drained into the collection reservoir300, it can be held there or drained out of the chamber12through a drain pipe44. For example, one or more storage containers (not shown) made of concrete, metal, composites, or another material may be provided beside or some distance from the trap10and connected to it by the drain pipe44.

In a typical commercial embodiment, the collection reservoir300is made of a rectangular metal box that is mounted to the chamber sidewalls18and20. Also, the opening316is in the shape of a horizontally elongate notch, and the weir314is provided by a horizontally elongate steel plate. For typical inlet and chamber sizes, the reservoir bottom wall is positioned about 1½ feet above the chamber floor so that the cross-sectional area of the reservoir gap is three to five times larger than the inlet. And the cross-sectional area of the rear sub-chamber is about eight to ten times larger than the inlet. In this configuration, the water flow rate through the trap is kept under about 1.0 feet per second even during the maximum storm event, which is slow enough to enable the trap to collection about 2 inches of particulate matter in typical installations.

Alternatively, the collection reservoir and its components may be provided in other regular or irregular shapes. For example, the collection reservoir can be triangular or have a front wall and/or weir that is curved, corrugated, zigzagged, or otherwise configured so that the skimming edge is longer to produce increased skimming of the floating matter. Similarly, the skimming edge may have a profile (when looking from the front) that is linear, serrated, has a series of notches, or that is otherwise configured. Also, the opening can be in the shape of a horizontal slot, a hole, or another-shaped opening with an upper portion of the front wall extending above it. In addition, the reservoir gap and the rear sub-chamber can be configured in other sizes and shapes selected for the site conditions. And instead of the collection reservoir being an open-top box, the reservoir sidewalls can be eliminated and the reservoir front, rear, and bottom walls mounted directly to the chamber sidewalls.

FIGS. 10A-10Edepict several alternative embodiments of the collection reservoir.FIG. 10Ais a plan view, whileFIGS. 10B-10Eare side views.

In a first alternative embodiment shown inFIG. 10A, the collection reservoir300ahas a curved front wall302a. In this way, the skimming edge is longer, so more floating matter can be skimmed into the reservoir300aduring larger-than-typical storms.

In a second alternative embodiment shown inFIG. 10B, the collection reservoir300bforms a tapered gap47bthat is larger closer to the rear of the reservoir than at the front of it. In this way, the water slows as it approaches the chamber outlet, so the particulate matter carried by the water loses momentum just as the water begins to flow up toward the outlet, which encourages the particulate matter to settle to the chamber floor22b.

In a third alternative embodiment shown inFIG. 10C, the collection reservoir300cincludes a float322cfor automatically adjusting the weir312c. The float322cis coupled to the weir312cby, for example, a rigid member324c. And the weir312cis mounted to the front wall302cso that it can slide up and down, without leaking. The float322cmay be provided by a hollow or low-density ball, a gas-filled shell of a lightweight but durable material such as plastic, or by another buoyant structure that will float on the water surface. The construction of the float322cand its coupling to the weir312care selected so that float positions the skimming edge304cof the weir at about the water level. During typical storms with water levels below the worst storm water level, the float322cand the weir312cautomatically adjust downward to the lower water level so that the collection reservoir300cskims the floating matter even at these lower flows. And, of course, as the water level rises, the float322crises with it to automatically keep the weir312cat the then-current water level. In this way, the collection reservoir300cis skimming the floating matter whenever there is a flow of water through the chamber.

In a fourth alternative embodiment shown inFIG. 10D, the collection reservoir300dis at the rear of the chamber12dand extends to the chamber floor22d, the outlet28dis in the one of the chamber sidewalls, and a riser pipe326dextends from the outlet28d. And in a fifth alternative embodiment shown inFIG. 10E, the collection reservoir300eis at the rear of the chamber12e, the outlet28eis below the reservoir, and a riser pipe326eextends from the outlet28e. The fourth and fifth alternative embodiments300dand300ecan be used in applications where there are very tight space limitations and/or where oil separation is the primary objection and particulate settling is not as important.

Referring now toFIGS. 1,2, and11, the pivotal filter400pivots from a filtering position402when a typical flow of the water is flowing through the chamber12toward a bypass position404during a larger-than-typical water flow. During a typical flow of the water through the chamber12, the weight of the pivotal filter400urges it down into the filtering position402. In the filtering position402, at least part of the pivotal filter400is at or below the at-rest liquid level32so that when the water flows through the chamber12, all or most all of the water passes through and is filtered by the pivotal filter.

But as the water flow increases during a larger-than-typical storm, the flowing water pushes the filter400pivotally out of the way toward the bypass position404to allow some-to-all of the water to bypass it. In the bypass position404, the pivotal filter400is pivoted upward enough so that the water flow rate is not reduced during the worst storm event. For example, during the worst storm event, the pivotal filter400may need to pivot enough out of the way that it does not filter any water, or it may only need to pivot far enough out of the way to allow only some of the water to bypass the filter, with some of the water still filtering though it. In any event, the pivotal filter400filters the water during typical storms, but does not reduce the water flow rate through the chamber12during the worst storm event for which the trap10is intended. And as the storm water flow subsides, the pivotal filter400pivots back down toward the filtering position402under its own weight.

In addition, the pivotal filter400preferably extends substantially all the way across the chamber12. That is, the ends of the pivotal filter400are positioned adjacent to the sidewalls18and20of the chamber12. In this configuration, none or only very little of the water can flow around the ends of the pivotal filter400and out of the chamber12.

Turning now to the construction of the pivotal filter400, in a typical commercial embodiment it is provided by a filtration member406that is supported by a frame408. For example, the filtration member406may be made of a ¼ inch thick slab of coconut fiber for filtering clay particulate matter. Alternatively, the filtration member406may be made of another material with another shape and/or size for filtering another pollutant.

The frame408has peripheral frame members410for supporting the filtration member406and defining a filtering opening411. In addition, the frame408has at least one open side412through which the filtration member406can be removed and through which a replacement one can be reinserted. Alternatively, the frame408can enclose all the filtration member406sides, with the frame and the filtration member being replaced together when needed.

In addition, the pivotal filter400is pivotally coupled within the chamber12by one or more pivotal couplings414such as hinges at one end of the pivotal filter. The pivotal couplings414may be connected to the collection reservoir300, the chamber sidewalls18and20, or to another component of the pollution trap10. For example, the pivotal filter400may be hinged to the rear or bottom wall of the collection reservoir300. Or it can pivot on horizontal pins that extend into the chamber sidewalls18and20. And the other end of the pivotal filter400may be positioned so that it leans against the end wall28of the chamber12, below the outlet28.

The size, shape, configuration, and pivotal coupling position of the pivotal filter400are selected depending on the particular application. For example, in a first alternative embodiment of the pivotal filter shown inFIG. 12, the filter400aincludes a frame408aprovided by a channel that receives the filtration member406a. In other alternative embodiments, the pivotal filter is positioned under the collection reservoir (as shown in FIG.10E), is provided without a frame, is provided with a differently configured frame, and/or extends only part of the way across the chamber.

Referring now toFIGS. 13-15, the operation of the pollution trap10of the first exemplary embodiment will now be described.FIG. 13depicts the pollution trap10in the at-rest state, when no water34is flowing into or out of the chamber12. In this state, the at-rest water level32is defined at the bottom of the outlet28, because no more water34can flow out of the chamber12. Because the screen100is above the at-rest water level32, any miscellaneous debris in the screen from previous storms dries out so it does not waterlog.

FIG. 14depicts the pollution trap10in operation during a typical storm, with a typical water flow level31in the chamber12that is between the at-rest level32and the worst storm water level30. In this state, the water34flows into the chamber12through the inlet26, carrying with it pollutants such as the miscellaneous debris36, particulate matter38, and floating matter40. Upon entering the chamber12, the water34flows through the screen100. But some or all of the vegetative matter, paper, plastic, and/or other miscellaneous debris36is retained by the screen100and suspended above the at-rest water level32so it does not waterlog, rot, and pass through the screen.

The water34then flows down into the chamber12and some of the sand, grit, and/or other particulate matter38settles to the chamber floor. Next the water34flows around the baffles to induce additional settling. Some of the water34and particulate matter38flows back up and through the first baffle top gap while some of it flows downstream through the apertures in the first baffle200′. Most of the water34and particulate matter38then flows down, through the bottom gap of the second baffle200″, and under the collection reservoir300, while some more of the particulate matter38settles to the chamber floor. Then the water34flows back up toward the outlet28. The water34flows through the pivotal filter400, through the outlet28, and out of the chamber12. But some of the clay and/or other particulate matter38still suspended in the water34is filtered and retained in the chamber12by the pivotal filter400.

At the same time, the motor oil, other hydrocarbons, detergents, and/or other floating matter40is carried through the inlet26and into the chamber12along with the water34. Some of the floating matter40stays on the surface of the water34and floats over the first baffle200′ through its top gap. And some of the floating matter40is forced down with the water34upon entering the chamber12, though its buoyancy causes it to flow to back up toward the surface of the water34. Some of this temporarily submerged floating matter40flows back up and through the first baffle top gap while some of it flows downstream through the apertures in the first baffle200′.

In any event, the floating matter40then flows through the apertures in the second baffle200″ and towards the collection reservoir300. By this time, most-to-all of the floating matter40is on the surface of the water34. The floating matter40builds up into a thick blanket until it is high enough to pass over the skimming edge and fall down into the collection reservoir. The floating matter40can be held in the collection reservoir300or drained into a separate storage container.

FIG. 15depicts the pollution trap10in operation during the worst storm event for which it was designed, when the trap is processing the maximum water flow rate through the chamber12. In this state, the worst storm water level30is defined by the skimming edge of the collection reservoir300. Thus, the water level30is at the same height as the collection reservoir skimming edge, so the trap10is at its maximum operating capacity. But even in this state, the top of the second baffle200″ is above the worst storm water level30, so that the water34cannot flow over the second baffle but instead is encouraged to flow down and under it.

In addition, with the increased water flow rate through the chamber12, the surging water34pushes the pivotal filter400up and out of the way, toward the bypass position. Now, since the water34is not flowing through the filter400, it is not impeded by it. Then after the storm subsides, the pivotal filter400falls back down into the filtering position shown inFIGS. 13 and 14. Furthermore, after the storm subsides, the miscellaneous debris36retained by the screen100will be above the at-rest water level32, so it can dry out and not waterlog.

To install the pollution trap for operation, the chamber is hauled to the installation site and lowered into a pit in the ground using conventional construction equipment. Then the inlet and the outlet are connected to the storm sewer system pipes. For retrofit installations, the existing storm sewer pipes are cut into and the pollution trap installed in-line. For new installations, the new storm sewer pipes are cut to length and connected to the trap. After installing any oil storage containers and/or bypass pipes, the pit is backfilled and the pollution trap is now ready for use.

The storage containers may be installed to hold the hydrocarbons, detergents, and/or other floating matter skimmed into the collection reservoir. This is typically done when a larger volume of floating matter needs to be stored than can be retained in the collection reservoir. For example, one or more containers can be lowered into a pit beside or some distance from the trap, and the drain pipe can then be connected between it and the collection reservoir.

Also, the bypasses may be installed to allow for storms that are worse than the worst storm event for which the trap is intended. For example, a bypass opening can be provided in the chamber above the worst storm water level, and a bypass pipe or the like extended from the bypass opening for directing the bypassed water to above the ground or elsewhere.

As mentioned above, the pollution trap10can be configured in a variety of different ways, with different combinations of the screen, baffles, collection reservoir, and pivotal filter filtration stages100-400. The chamber is sized smaller or larger as needed to house the filtration stages selected for the particular application.

For instance, the pollution trap can be provided with only the screen in applications where filtering vegetative matter or other miscellaneous debris is the primary objective. Alternatively, the trap can be provided with only the baffles in applications where separating particulate matter is the primary objective and/or when the trap is used to treat the water before directing it into another pollution trap. Or both of these stages can be included, but not the collection reservoir, for separating miscellaneous debris and particulate matter but not oil.

As another example, where the primary objective is separating oil or another floatable pollutant, and little or no vegetative and particulate matter is carried by the water, then the pollution trap could be provided with only the collection reservoir. If desired, the screen or a modified version of it could be included to catch any large stray debris that finds its way into the chamber. In addition, where there are space limitations that restrict the size of the front sub-chamber, the baffles could be included to allow most to all of the oil time to get back to the water surface for skimming.

In still another example, the trap is provided with only the pivotal filter, which can be mounted to the chamber sidewalls. This embodiment might be preferable where the primary goal is filtering large amounts of clay or other particular matter. Of course, the pivotal filter can be included with any other of the filtration stages, as may be desired for a given application.

In yet another example, where the primary objective is separating oil or another floatable pollutant, and little or no vegetative and particulate matter is carried by the water, the pollution trap is provided with only the collection reservoir. If desired, the screen or a modified version of it can be included to catch any large stray debris that finds its way into the chamber. And where there are space limitations that restrict the size of the front sub-chamber, the baffles can be included to allow the oil time to get back to the water surface for skimming.

Also, multiple traps can be connected together, with different of the traps having the same or different of the filtration stages. For example, one trap can be configured with the collection reservoir for processing oil during the “first flush” storm event when most of the oil on paved parking lots and streets is flushed away. And another trap can be configured with the baffles for settling particulate matter after the first flush, and connected to the first trap so that it comes on line after the first flush event.

FIG. 16shows a method600for maintaining the pollution trap in good working condition. The maintenance procedure600can be performed to clean out the trap as needed (such as after a series of particularly severe storms) and/or at regular intervals. For example, every three months or so a conventional vacuum truck can be dispatched to the site to clean the trap.

To perform the cleaning, at602the lid is opened to gain access to the inside of the chamber, then the retained pollutants are removed for disposal offsite. Thus, at604the miscellaneous debris is removed from the screen, at606the settled particulate matter is suctioned from off the chamber floor, and at608the floating matter is suctioned out of the collection reservoir and/or the storage container. The miscellaneous debris is removed from the screen at604by suctioning it up while the screen is in the chamber, or by removing, emptying, and replacing the screen. And before removing the floating matter at608, the maintenance plug may be removed or the weir lowered to allow some or all of the floating matter built up in the front sub-chamber to drain into the collection reservoir and/or the storage container. Of course, afterwards the plug is reinstalled or the weir returned to it operating position. After the oil is removed, it can be recycled for future use, if desired.

In addition, at610clay or other particulate matter retained by the pivotal filter is removed. For example, the filtration member of the pivotal filter can be removed then cleaned and replaced or a new one installed if needed. And finally, at612, the lid is closed. No other regular maintenance is required. The trap is now clean and ready to return to service.

Referring now toFIGS. 17 and 18, there is illustrated a second exemplary embodiment of the present invention, referred to generally as the portable clean-up apparatus1000. The portable clean-up apparatus1000can be used to clean up spills, leaks, or other accumulations of floating pollutants such as oil, gasoline, detergents, or a combination of these, whether on land or water. Thus, the portable clean-up apparatus1000can be used to clean up spills or leaks from pipeline bursts, tanker leaks (including ships and tractor trailers), gas station fuel tanks, and so forth.

The portable apparatus1000includes a vehicle1001carrying a pollution trap1010and a trap operating system1002. The vehicle1001can be provided by a flatbed truck, another type of truck or automobile, a ship, boat, or submarine, a rail train car, a platform suspended in the air, or any other transportation device selected to support the components of the apparatus1000for a particular clean-up application. Alternatively, the pollution trap1010and the trap operating system1002could be permanently installed at a particular location that is inaccessible by vehicles and/or that experiences frequent spills.

The pollution trap1010may be provided by one similar to any of those described herein. Thus, the pollution trap1010can be configured with a screen, baffles, a collection reservoir, and a pivotal filter (similar to the first exemplary embodiment), or with only one or a combination of these filtration stages.

Turning now to the details of the trap operating system1002, it includes a tank1003, a pump1004, and a hose1005, which may be provided by conventional equipment known in the art. The water tank1003holds water or another liquid selected for floating the targeted pollutant, the water output pump1004draws the water out of the water tank, and the water hose1005directs the water toward the spill. In this way, the water in the tank1003can be sprayed at the oil or other floating pollutant so that they flow into a collection pool1006where the pollution floats in the water.

Alternatively, the tank1003, pump1004, and hose1005need not be provided where another water source is available to supply the pooling water. For example, these components need not be provided in the operating system1002when a conventional water hydrant is available, a separate tanker or pumper truck is used, or when the clean-up apparatus1000is used on a ship or boat and the targeted pollution is already floating on water. And the trap operating system1002can be provided with the pump1004and hose1005, but not the water tank1003, in applications where water can be drawn from a nearby retention pond or the like.

In addition, the trap operating system1002includes another pump1007and another hose1008, which may be provided by conventional equipment known in the art. The polluted water pump1007draws the polluted water from the collection pool1006, through the polluted water hose1008, and into the pollution trap1010. The polluted water then flows through the pollution trap1010, which separates the pollutants from the water.

Furthermore, the trap operating system1002includes a conventional storage tank1009for storing the pollution separated from the water by the pollution trap1010. The separated pollution storage tank1009may be connected to the pollution trap1010by a pipe1011, the pollution tank1009may be positioned under the trap1010, and/or they may be arranged otherwise to deliver the separated pollutant to the pollution storage tank. And the water separated from the pollution may be delivered to another tank (not shown) for storage, into the storm sewer system, into a lake, stream, or ocean, or back into the water tank1003for reuse. For example, the separated water can be delivered to the water tank1003by a pipe1013. The separated water and the separated pollutant can be drawn out of the pollution trap1010by additional pumps (not shown) or they can flow by gravity. Also, the separated pollutant can be delivered to a secondary pollution trap (not shown) for further processing, if desired.

FIG. 19shows an alternative portable pollution trap1010athat can be used in the clean-up apparatus1000of the second exemplary embodiment. In this embodiment, the pollution trap1010aincludes a chamber1012awith an inlet1026aand an outlet1028a, and a collection trap1300ahoused in the chamber. This embodiment may be preferred in clean-up applications where the primary objective is separating floating pollutants from liquid, and filtering other pollutants is less important. For example, when using a boat-mounted clean-up apparatus to clean up oil spills on the ocean, there is typically very little grit and/or vegetative matter that needs to be separated from the seawater.

FIG. 20shows a method1600for using the portable clean-up apparatus to clean up spills of oil, gasoline, detergents, or other floatable pollutants. To use the portable clean-up apparatus, it is first transported to the spill site by land, water, or otherwise. Then the pollution trap and the trap operating system are operated to clean up the spill and store the cleaned-up pollution. And finally the stored pollutant is properly disposed of, and the portable clean-up apparatus removed from the site.

To operate the trap operating system and the pollution trap to clean up the spill, at1602the floatable pollutant is first floated on water or other liquid in a collection pool. For spills on land, the water or other liquid in the water tank is aimed at the floatable pollutant to direct it into the collection pool. For example, the water pump can be operated to draw the water from the water tank, and the water hose aimed to spray the water onto bushes, grass, the ground, or elsewhere. Alternatively, where another water source such as a water hydrant is available, it can be used instead of the water tank pump, and hose. Or where the clean-up apparatus is carried on a ship or boat and the pollution is already floating on water, step1602need not be performed.

Next, at1604, the polluted water is drawn from the collection pool and into the pollution trap. For example, the polluted water pump can be operated to draw the polluted water from the collection pool, through the polluted water hose, and into the pollution trap. The polluted water then flows through the pollution trap, which skims or otherwise separates the oil or other pollutant from the water.

After the pollution and water are separated, at1606the separated pollution is delivered from the pollution trap to the pollution storage tank, for example, through the separated pollution pipe. The oil, gas, or other pollution can then be hauled away and disposed of or recycled. And at1608the separated water is removed from the pollution trap. For example, the separated water may be delivered from the pollution trap through the separated water pipe to the water tank for reuse. Alternatively, the separated water may be delivered to the storm sewer system, a lake, stream, or ocean, or it may be otherwise disposed of. Of course, the separated water and the separated pollutant can be delivered from the portable pollution trap to the separated water tank and the separated pollutant tank, respectively, by additional pumps, or they can flow by gravity.

Accordingly, the present invention provides innovative pollution traps that provide a number of advantages over other known oil/grit separators. For example, the pollution traps stay on-line during larger-than-typical storms, without bypassing or overflowing, to remove and trap more pollutants from storm-water runoff than other oil/grit separators. In addition, in one form the present invention provides a pollution trap with a pivotal filter that filters clay and other particulate matter during typical flows but that automatically pivots to a bypass position, without causing a bypass of any other of the filtration stages, during larger-than-typical storm flows. In a combination form the present invention also provides a pollution trap with a uniquely configured screen that reduces waterlogging of absorbent miscellaneous debris and disperses the storm water upon entering the trap to provide improved filtration of the storm water. In yet another combination form the present invention also provides a pollution trap with baffles that disperse and increase the residence time of the water to better induce settling of particulate matter within the trap. And in still another combination form the present invention also provides a pollution trap with a collection reservoir for skimming hydrocarbons and other floating matter and dividing the chamber into sub-chambers to further induce settling of the particulate matter. The pollution trap in these forms is cost-efficient to build, install, and maintain.

In the embodiments described above and in the following claims, the words “a,” “an,” and “one” are not intended to mean “only one” but can also mean any number greater than one. Similarly, plural terms are sometimes used for convenience and are not necessarily intended to mean “more than one” but can also mean just “one.”Additionally, the methods are not intended to be limited to the particular sequence of steps described.

While the invention has been shown and described in exemplary forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions can be made therein without departing from the spirit and scope of the invention as set forth in the following claims.