Recovery and control system for leachate collection

• US 4,727,936 A
• Filed: 04/24/1986
• Issued: 03/01/1988
• Est. Priority Date: 02/28/1983
• Status: Expired due to Term

• Current Assignee: Q.E.D. Environmental Systems, Inc. (Graco Incorporated)
• Original Assignee: Q.E.D. Environmental Systems, Inc. (Graco Incorporated)
• Inventors: Edwards, David H., Fischer, David A., Mioduszewski, David
• Primary Examiner(s): Novosad, Stephen J.
• Assistant Examiner(s): Kisliuk, Bruce M.
• Application Number:
  US06/855,437
• Time in Patent Office: 677 Days
• Field of Search: 166/250, 166/52-54, 166/64, 166/60, 166/72, 166/105, 166/264-267, 405/128, 405/129, 210/901, 417/36, 417/38, 417/46, 417/394, 417/478, 417/479, 137/565, 137/566, 137/571, 137/627, 73/155, 73/302, 73/864.34
• US Class Current: 166/53
• CPC Class Codes: E21B 43/129 Adaptations of down-hole pump systems powered by fluid supplied from outside the borehole gas-lift E21B43/122; jet pumps E21B43/124
• CPC Class Codes: E21B 43/13 specially adapted to dewatering of wells of gas producing reservoirs, e.g. methane producing coal beds
• CPC Class Codes: E21B 49/084 with means for conveying samples through pipe to surface
• CPC Class Codes: G01N 1/14 Suction devices, e.g. pumps; Ejector devices

Abstract

A fluid sampling apparatus is disclosed for withdrawing samples of groundwater or other fluids from a well or other monitoring site. The apparatus preferably includes pump means, conduit means and a wellhead assembly that are substantially permanently installed at such well or monitoring site and are thereby dedicated thereto in order to avoid or minimize cross-contamination of samples from site to site. The apparatus preferably also includes a removable and portable controller means adapted for easy and convenient transportation and connection to such dedicated fluid sampling components at various wells or monitoring sites. A recovery, collection and control system for cleanup of leachate or other liquid material or contaminated groundwater from a landsite is also disclosed. Such system preferably includes fluid-operated pump means, each with associated preferably pneumatic controller apparatus, as well as a collection system for collecting, monitoring and controlling the collection and disposal of hazardous or other material withdrawn from in-ground wells at the landsite.

Claims

1. In a system for removing a flowable liquid material from a contaminated landsite having at least one in-ground well, a gas-operated submersible pump for withdrawing the liquid material from the in-ground well, and a source of pressurized gas, the improvement comprising a gas control apparatus for selectively actuating and deactuating the gas-operated pump, said gas control apparatus including:

well level sensing means for sensing the level of the liquid material in the in-ground well, said level sensing means including a static head conduit having an open end extending below the surface of said liquid material in the in-ground well and a second end in fluid communication with a source of a first measuring fluid, said level sensing means including means for supplying said first measuring fluid to asid static head conduit at a pressure sufficient to force a portion of said first measuring fluid out of said open end against the static head of the liquid material, and means for measuring and controlling the pressure of said first measuring fluid in order to determine the level of the liquid material in the in-ground well;

first control means for selectively actuating the gas-operated pump in response to the sensing of a predetermined high liquid material level in the in-ground well and for selectively deactating the gas-operated pump in response to the sensing of predetermined low liquid material level in the in-ground well in order to thereby control the level of the liquid material level in the in-ground well;

a liquid collection tank and means for conveying the liquid material from the gas-operated pump to said collection tank for collection therein; and

tank level sensing means for sensing the level of the liquid material collected in the collection tank, said tank level sensing means including a second static head conduit having an open end extending below the surface of said liquid material collected in the collection tank and a second end in fluid communication with a source of a second measuring fluid, said tank level sensing means including means for supplying said second measuring fluid to said second static head conduit at a pressure sufficient to force a portion of said second measuring fluid out of said open end of said second static head conduit against the static head of the liquid material, and means for measuring and controlling the pressure of said second measuring fluid in said second static head conduit in order to determine the level of the liquid material collected in the collection tank; and

second control means for selectively preventing actuation of the gas-operated pump in response to the sensing of a predetermined high liquid material tank level in said collection tank and for permitting actuation of the gas-operated pump in response to the sensing of a liquid material tank level in said collection tank below said predetermined high liquid material tank level.

2. The invention according to claim 1, wherein said gas-operated pump is a pneumatic pulse-tupe gas displacement pump, and wherein said pressurized gas is compressed air.

3. The invention according to claim 1, wherein said gas-operated pump is a pneumatic diaphragm-type pump, and wherein said pressurized gas is compressed air.

4. The invention according to claim 1, wherein at least the components of said gas-operated pump, said control means, and said collection tank that are adapted to be contacted by the liquid material are composed of a non-corroding synthetic material.

5. The invention according to claim 1, further including the improvement wherein said pumping means is a gas-displacement pump including:

a pump body submersible in the in-ground well and having a generally hollow pump body interior, said pump body having liquid inlet means including an inlet check valve for providing substantially one-way fluid communication from the in-ground well into the pump body interior, and outlet means including an outlet check valve for providing substantially one-way fluid communication from the pump body interior to the collection system;

a discharge tube disposed within said pump body interior in a spaced relationship therewith and having an open inlet end therein, said discharge tube further having a discharge end in sealed fluid communication with said outlet means;

said first control means including gas supply means for selectively providing fluid communication between the gas source and the pump body interior in order to actuate said pump, said gas supply means including means for sequentially and pulsatingly supplying pressurized gas into said pump body interior in order to forcibly displace the liquid material therein outward through said discharge tube and said outlet means and then relieving the pressure of the gas in the pump body interior in order to permit the liquid material to flow into said pump body interior through said inlet means.

6. The invention according to claim 5, wherein said inlet means includes an inlet filter screen for permitting said one-way fluid communication therethrough and for substantially preventing passage of solids greater than a predetermined size therethrough.

7. The invention according to claim 6, wherein said pump is composed substantially entirely of non-corroding synthetic material.

8. The invention according to claim 1, further including a containment structure substantially surrounding at least the gas-operated pump and said means for conveying the liquid material from the gas-operated pump to said collection tank for substantially preventing the relase of the liquid material to the environment therefrom.

9. The invention according to claim 8, further including drain means for draining any leakage of liquid material in said containment structure back into the in-ground well.

10. A system for withdrawing and collecting a flowable liquid material from a landsite having at least one in-ground well, a collection system for collecting the withdrawn liquid material, and a source of pressurized gas, said system comprising:

a gas-operated pump submersible in said in-ground well, said pump including;

a generally hollow pump body having a generally hollow interior and an inlet means including an inlet check valve for providing

substantially one-way fluid communication from the in-ground well into the pump body interior, and outlet means including an outlet check valve for providing substantially one-way fluid communication from the pump body interior to the collection system; and

a discharge tube disposed within said pump body in a spaced relationship therewith and having an open end, said discharge tube further having a discharge end in sealed fluid communication with said outlet means;

a liquid collection tank and means for conveying the liquid material from said gas-operated pump to said collection tank; and

gas control apparatus for controlling the operation of said gas-operated pump, said gas control apparatus including;

well level sensing means for sensing the level of the liquid material in the in-ground well, said well level sensing means including a static head conduit having an open end extending below the surface of said liquid material in the in-ground well and a second end in fluid communication with a source of a first measuring fluid, said well level sensing means including means for supplying said first measuring fluid to said static head conduit at a pressure sufficient to force a portion of said first measuring fluid out of said open end against static head of the liquid material, and means for measuring and controlling the pressure of said first measuring fluid in order to determine the level of the liquid material in the in-ground well;

actuation means for selectively actuating said gas-operated pump in response to the sensing of a predetermined high liquid material in the in-ground well and for selectively deactuating said gas-operated pump in response to the sensing of a predetermined low liquid material level in the in-ground well;

timer means for sequentially and pulsatingly pressurizing and depressurizing said pump body interior for respective first and second time periods during said actuation of said gas-operated pump, the liquid material in said pump body interior being displaced and forcibly discharged through said discharge tube and said discharge means when the gas in said pump body interior is pressurized, and the liquid material in said in-ground well being allowed to flow into said pump body interior when the pressure of the gas in said pump body interior is relieved; and

tank level sensing means for sensing the level of the collected liquid material in the collection tank, and shut-off means for preventing actuation of said gas-operated pump in response to a predetermined high liquid material level in the collection tank, said tank level sensing means including a second static head conduit having an open end extending below the surface of said liquid material in the collection tank and a second end in fluid communication with a source of a second measuring fluid, said tank level sensing means including means for supplying said second measuring fluid to said second static head conduit at a pressure sufficient to force a portion of said second measuring fluid out of said open end of said second static head conduit against the static head of the liquid material, and means for measuring and controlling the pressure of said second measuring fluid in said second static head conduit in order to determine the level of the liquid material in the collection tank.

11. The invention according to claim 10, wherein at least said gas-operated pump is composed substantially entirely of non-corroding synthetic materials.

12. The invention according to claim 10, wherein said system includes a plurality of said pumps for withdrawing a flowable liquid material from a landsite, said collection tank comprising a flow totalization vessel for receiving and collecting the liquid material from a least a number of said pumps, said flow totalization vessel including cyclable automatic syphon means self-actuable for discharging a predetermined volume of said collected liquid material to a disposal system, when said collected liquid material accumulates to a first predetermined discharge level in said flow totalization vessel, said automatic syphon means being self-deactuable when said collected liquid material is reduced to a predetermined holding level in said flow totalization vessel, said flow totalization vessel including a mechanical counter for counting the number of actuation-and-deactuation cycles of said discharge means in order to measure the total volume of the collected liquid material discharge from said flow totalization vessel over a preselected time period, said cyclable discharge means further including overflow discharge means for discharging said collected liquid material to said disposal system in the event that said collected liquid material in said flow totalization vessel reaches a second predetermined discharge level in excess of said first predetermnined discharge level.

13. The invention according to claim 10, further including a containment structure substantially surrounding at least the gas-operated pump and said means for conveying the liquid material from the gas-operated pump to said collection tank for substantially preventing the release of the liquid material to the environment therefrom.

14. The invention according to claim 13, further including drain means for draining any leakage of liquid material in said containment structure back into the in-ground well.