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Groundwater Remediation

Groundwater Remediation

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Groundwater Remediation

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  1. GroundwaterRemediation EPA Region III Superfund Site Sarah Shaffer Honors Engineering Science I

  2. Importance of Groundwater Drinking water and wells

  3. Pennsylvania Water Use • In Pennsylvania, public supply water makes up 14% of total water supply and 30% comes from rural supply. • 100% of PA’s water comes from underground sources.

  4. The Hydrologic Cycle • Precipitation • Run off • Recharge • Saturated Zone • Impervious Rock Bed • Water Table • Evaporation • Transpiration

  5. Drinking Water Standards • MCGL ( Maximum Contaminate Goal Level) is set for the contaminate. • MCL (Maximum Contaminate Level) is then set for contaminate. • EPA sets standards and tests wells for contaminates.

  6. Tranguch Site History EPA Region III Superfund Site.

  7. Investigation • Between Sep. 1993 and Jan. 1994 the sewer systems were inspected. • Gas was found to have infiltrated the sewer system • DEP began monitoring indoor air conditions in 48 homes surrounding Tranguch.

  8. Oh how I wish for my ions to dissolve and reapear here.

  9. Responsibility • 7 Active or closed body shops, gas stations and garages were initially thought to be responsible. • Formal notices were issued to these businesses to conduct site characterizations.

  10. Site Characterization • The Site Characterization preformed by these businesses required- • The testing of Underground Storage Tanks (UST’s) for any leaks, cracks or possible contamination. • The analysis of the soil under and around the tanks to determine if any signs of earlier or present day contamination is evident.

  11. Contamination Study • Routine sampling of 20 groundwater monitoring wells. • Thorough study of mining data and maps. • Groundwater sampling survey. • Analysis and plotting of all data. • 50 samples taken up and down gradient. • Time period: 1993-1995.

  12. Contamination Determined • The site characterization was completed and the contaminated area was found to be, from Tranguch, south to 17th street; north to 23rd street; east to Meade street; and west to Routes 309-940.

  13. Biological Effects of BTEX

  14. Benzene • The maximum contaminate level goal is set at 0 • The maximum contaminate level is set at 5 parts per billion. • Total releases of benzene between 1987 and 1993 total over 2 billion lbs.

  15. Benzene in Water • Benzene is somewhat soluble in water making it hard to remediate. • If benzene is in surface water it will evaporate. • Benzene can contaminate wells if present in groundwater.

  16. Acute Myelogenous Leukemia • Acute Myelogenous Leukemia is the rapid progression of a cancer of the blood, characterized by an overproduction of immature white blood cells taking majority of the bone marrow.

  17. Health Effects • Twenty or more years may pass before symptoms are noticed. • Known to cause Acute Myelogenous Leukemia.

  18. Health Effects (cont.) • Benzene also causes: • Anemia • Excessive bleeding • Decreased ovary size • Menstrual disorders • Impair fertility • Damage to nervous system. • Increase in infection chances. • Lung and bladder cancers

  19. Surprise!!!!! • A major portion of Benzene contamination is found in cigarette smoke. • Benzene traces are also found on meat, eggs, fruit and vegetables.

  20. How Benzene Causes Harm • Enters bloodstream. • Carried into bone marrow and fatty tissues • Passes through liver and is broken down • Harmful metabolites are formed. • Some Health problems are caused by these metabolites present in the body.

  21. Ethyl Benzene • Ethyl benzene is a benzene derivative and it behaves much like benzene in the environment and in water. The health effects are also very similar.

  22. Toulene • Toulene (or methyl benzene) is also another benzene derivative, therefore it also behaves like benzene in reference to the environment and health effects.

  23. Xylene • Xylene is 6- 15% ethyl benzene. • Another name is dimethyl benzene. • It also behaves like benzene in reference to environment and health problems.

  24. Naphthalene • No mcl set by EPA. • White solid. • Used as insect repellent. • Also present in water at Tranguch.

  25. In Situ Bioremediation • Managed or spontaneous process • Microbiological process used to degrade or transform contaminates into non toxic forms. • Therefore mitigating or eliminating contamination.

  26. Basically…. They send little bugs down wells and they keep the bugs alive so that the bugs can eat the contaminates and leave behind traces of non toxic substances such as water and carbon dioxide.

  27. Techniques of Remediation

  28. Electrokinetics • Elecktrokinetics seprates and extracts contaminates from soils, sludges, sediments and groundwater. • Goal is to effect migration of contaminates in an imposed electric field via electroosmosis, electromigration, and electrophoresis. • It works when the soil is electrically charged with a low voltage current.

  29. Basically…. • They give water, soil and sludge a shot of electricity and through the use of several different biological occurances, the contaminate is shocked out of the stuff.

  30. In Situ Flushing • In Situ flushing involves the injection or infiltration of an aqueous solution into a zone of contaminated soil/groundwater. • This is then followed by a downgradient extraction of groundwater and elutriate (flushing solution mixed with contaminates.) and aboveground treatment and discharge or re- injection.

  31. Basically…. • In Flushing they send down a mixture that flows down the plume and catches the contamination before they pump the water back out and treat it. • It basically helps make the treating job easier for the equipment.

  32. Air Sparging • Air sparging involves injecting a gas (usually air or oxygen) under pressure into the saturated zone to volatize groundwater contaminates and to promote biodegradation in saturated and unsaturated soils by increasing subsurface oxygen concentrations. • They are then extracted using a vacuum, generally by soil vapor extraction systems. • This is an EPA approved method of remediation.

  33. Basically…. • Pressurized air is put into the water and increases the surface area making it easy to pull the contaminates off the surface area of the water. This uses Henry’s Law and will be discussed later.

  34. Bioslurping • Bioslurping involves the simultaneous application of vacuum enhanced vapor extraction, recovery and bioventing to address LNAPL contamination. • Vacuums are used to remove free product along with some groundwater and vapor extraction is used to remove high volatility vapors. • Bioslurping is made up of a well with an adjustable slurp tube that is lowered into the LNAPL layer and is used to pump contaminates out.

  35. Basically…. • A pump slurps up all the contaminates with a little bit of water. Kind of like slurping little pieces of chocolate leftover from your hot chocolate.

  36. Horizontal Wells • This technology can be incorporated into many other different technologies such as bioremediation, air sparging, vacuum, and soil flushing. • Their long horizontal form makes them suitable for covering a long range of contaminated area.

  37. Ultraviolet Treatment • UV disinfection works by exposing waterborne microorganisms to UV light at a specified intensity for a specified period of time. This process of germicidal UV light renders microorganisms , in effect, “microbiologically dead.” It does so by penetrating the cell wall and affecting the DNA in such a way that the cell cannot reproduce.

  38. Phytoremediation • Phytoremediation uses plants to cleanup contaminated soil and groundwater, taking advantage of the plants natural abilities to take up, accumulate, and or degrade constituents of their soil and water environments.

  39. Air Stripping • Air Stripping takes advantage of the effect of faster contaminate removal with greater surface area. It maximizes the amount of water in contact with air so the contaminate is removed quickly, generally in matter of seconds.

  40. Air Stripping • The most common use of air stripping is through a packed tower. • You can also use air stripping technology through aeration tanks, trays, but all use the same technology of large surface area and small amounts of water.

  41. Granular Activated Carbon • GAC consists of aprx. 1 mm sized carbon grains. Their effectivness depends on adsorption ( a process were a molecule adheres to the surface of a substance.) • The carbon is dehydrated, crystallized, heated with steam to create pores. This gives GAC a huge surface area. A handful of GAC has a larger surface area than ten football fields.

  42. Maxi Strippers Inventor: Randy Galgon Hazleton Environmental

  43. Maxi Strippers • The Maxi Strip SP technology is built on three foundational fluid dynamic concepts • Boundary Layer Control • Cavitation • Aspiration

  44. Maxi Strippers (cont.) • The maxi stripper accelrates the fluid stream on the undersidde of the deflector plate thereby reducing the thickness of the wall between liquid and gas. By reducing the size of this wall the resistance to mass transfer is lowered.

  45. Maxi Strippers vs. Packed Towers. • The difference between the Maxi Air Stripper and the conventional packed tower is the fact that a packed tower actually increases the resistance to mass transfer by increasing the thickness of this boundary layer wall. As the water spreads out over a piece of packing the boundary layers get thicker, increasing the resistance to mass transfer.

  46. Henry’s Constant • Henry’s constant is what enables all stripping systems to work. Sparging systems and various other pieces of equipment also rely on this law. Henry’s constant is found by dividing the Vapor Pressure over the solubility.

  47. EPA’s Site Characterization EPA Region III Superfund Site

  48. Water Chemistry • Ph: 7.1 • Total hardness: 84.4 mg/L • Iron: 8.2 mg/L • Manganese: 4.6 mg/L • Magnesium: 2.5 mg/L