\ ORDER FORM DRINKING WATER PUBLICATIONS DOCUMENT # TITLE/DESCRIPTION QUANTITY EPA816F02026 ***NEW*** Consumer Confidence Report Rule: A Quick Reference Guide - This is another in a series of quick reference guides we have prepared on our major rules. This one is not contained in the highly popular "Compilation of Quick Reference Guides" below. EPA816R03002 ***NEW*** Cross-Connection Control Manual - This manual has updated technical corrections to the original 1998 Manual EPA816H03001 ***NEW*** Source Water Protection - It's In Our Hands Poster - EPA816F03008 ***NEW*** Source Water Protection - It's In Our Hands Brochure to accompany poster above. EPA816K03003 ***NEW*** MCL Pocket Guide - Consumer Confidence Reports: Building Public Trust - This is the 2003 edition of the popular small pocket guide that contains all the MCLs EPA816H03002 ***NEW*** MCL Wall Chart - This is the 2003 edition of the wall chart listing all the MCL. This year's version shows them in alphabetical order with color codes for the contaminant groups. ------- EPA816H02003 EPA816F02015 EPA816B02001 11x17 inch version of the poster Safe Drinking Water Act - Protecting America's Public Health - This version has information on the flip side further explaining the multiple risks and barriers (great as a handout for board meetings, plant tours, classroom visits) Lesson Plan - Water: is It Safe To Drink? - Lesson plan for poster above Compilation of Quick Reference Guides Packet with one each of : Arsenic, Radionuclides, Long Term 1, Interim Enhanced Surface Water Treatment, Filter Backwash, Stage 1 DBPs Name: Affiliation: Address: Send form to: Charlene Shaw EPA/OGWDW/4606M 1200 Pennsylvania Avenue NW Washington, DC 20460 Or FAX: 202/564-3757 Email: Office of Water EPA816-F-03-021 July 2003 www. epa. gov/safewater ------- & Technology I News and Trends United States Environmental Protection Agency National Service Center for Environmental Publications P.O. Box 42419 Cincinnati, OH 45242 Official Business Penalty for Private Use $300 Solid Waste and Emergency Response (5102G) EPA 542-N-03-003 May 2003 Issue No. 6 First Class Mail Postage and Fees Paid EPA Permit No. G-35 [continued from page 5] electrode array during system startup. Placing a chain-link mesh outside the array and grounding it to a distant monitoring well remedied this problem. In addition a pre-pilot resistivity survey would have helped to assess the potential for undesired stray voltage during treatment. A significant setback was encountered during the second month of operation when cracks in the CPVC piping (leading from the electrodes to the vapor header) resulted in an atmospheric release of steam and vapor. Operations were shut down for several days but resumed after the degraded CPVC was replaced with flexible chemical-resistant hose. This unexpected condition appeared to result from a combination of excessive heat, pressure, and chemical attack from a variety of contaminants. Post-test analysis showed that shallow ground-water contamination (<24 feet bgs) in the treatment zone decreased more than 99%, and deeper ground-water contamination (24- 40 feet bgs) decreased more than 76%. Analytical results also indicated a 95% reduction in contaminated soil mass. Additional analysis of the pilot results will determine whether ERH technology could be used to achieve project cleanup goals that were not met through 1997-1998 implementation of a soil vapor extraction (SVE) system. Although SVE treatment resulted in the removal of approximately 12 tons of subsurface VOCs over a 14-month period, concentrations in the vadose and saturated zones remained significantly higher than their maximun contaminant levels. Results of the ERH pilot suggest that this technology can increase mass removal efficiencies in both the vadose and saturated zones more effectivaly than traditional SVE. The ERH pilot cost approximately $1.6 million, including $50,000 for electrical power and $50,000 for vapor treatment. Modeling based on total VOC concentrations exceeding 10 mg/kg indicates that 1.02 million tons of soil require additional treatment Contributed by Sharon Hayes, U.S. EPA/Region 1 (617-918-1328 or haves.sharon@epa.gov) and John Scaramuzzo, Tetra Tech FW, Inc. (617-457-8297 or jscaramu7zp@ttfwi.com) In the March 2003 Technology News and Trends article, "DNAPL Treatment Demonstration Completed at Cape Canaveral," the contributors believe use of the terms "treatment efficiencies" and "cleanup efficiencies" may be misleading due to uncertainties in mass removal estimates for the SPH demonstration. The appropriate language is "apparent mass reduction." The SPH cost of "$164" for each kg of TCE removed or destroyed should read "$64." EPA is publishing this newsletter as a means of disseminating useful information regarding innovative and alternative treatment techniques and technologies. The Agency does not endorse specific technology vendors. ------- [continued from page 2] 80% lower dissolved PCE concentrations than before treatment, with an average PCE concentration of approximately 15 mg/L. NRMRL and SERDP are preparing a comprehensive summary of these demonstration results, as well as the results of other innovative DNAPL remediation technologies recently tested at the DNTS. Contributed by A. Lynn Wood, U.S. EPA/ORD/NRMRL (580-436-8552 or wood.lynn@.epa.gov) and Ronald Falta, Clemson University (864-656-0125 or faltar@clemson.edu} Cumulative Amounts 90,000 80,000 70,000 c .o - - 60,000 1 o CO - - 50,000 o >-Cumulative PCE >- Cumulative n-propanoi - - 40,000 - - 30,000 - - 20,000 IS - -10,000 0.00 10.00 20.00 30.00 Time (days) 40.00 0 50.00 Figure 1. Cumulative profiles of PCE removal and n-propanol solution injection during cosolvenf flooding indicate that about 80% of the initial 92.3 kg of PCE in the test cell \vcts removed. Biosparging Used to Remove Chlorinated Solvents at the SRS Sanitary landfill As part of a comprehensive effort to address ground-water contamination at the U.S. DerrartmentofEnergy SavannahRiverSite(SRS) near Aiken, SC, a biosparging system began operating in 1999 at the site's sanitary landfill (SLF>- Biosparging was selected to address (he trichloroethene (TCE), vinyl chloride, and TCE breakdown products in the ground water underlying the landfill. By 2002, biosparging treatment had reduced ground-water concentrations of vinyl chloride and TCE within the treatment zone by 99% and 75%, respectively. Large amounts of wastes were generated at the SRS during construction and operation of,the facility. Cafeteria and office wastes, sewage sludge, miscellaneous construction materials, and debris routinely were disposed at the 70- acreunlinedSLF from the early 1970stothe mid 1990s. After the discovery of ground-water contamination beneath the landfill, the main section and the southern expansion area of the landfill were covered wilh an engineered cap. Maximum concentrations of vinyl chloride and TCE at interior landfill wells were 480 ug/L and 31 ug/L, respectively, prior to biosparging treatment Three significant hydrogeologic units underlie the landfill: an uppermost unconfined aquifer, a confining unit, and a lower aquifer. The depth to the water table ranges from 30 ft to 60 ft bgs. Ground-water flow in the area of me landfill is primarily horizontal, with an upward flow component where it discharges to a large wetland adjacent to the landfill. Beneath the landfill, contaminantswere identifiedority in.lhe upperportionsofthe shallow aquifer. Numerical modeling estimates that the advective transport time from the main section of the landfill to a downgradient biosparging well between the landfill and wetland is 11 years, with another three years for discharge 'to the wetland (Figure 2). Low dissolved oxygen levels observed after construction of the landfill cap suggested that reductive dechlorination of chlorinated compounds could occur beneath the landfill. Following successful field-scale testing of biosparging, a full-scale system was constructed. The system consists of two horizontal biosparging wells screened immediately below the vertical center of the contaminant plume: an 800-ft screened well downgradient of the landfill for treating TCE, and a 900-ft screened well side-gradientof the landfill for .treating vinyl chloride. Each well consists of a six-inch-diameter outer steel casing, screen, and an inner four-inch, high- densityvpolyelhylene liner. Botbwells rely on a central air compressor unit (rated for a maximum airflow of 540 cfm) but operate independently to accommodate different injection configurations. . Optimization testing prior to full-scale operations, demonstrated that additional nutrients were needed for the downgradient well area, white air injection wasmfequate for bioremediation in the side-gradient well area. Methane (0.7%) was injected into the downgradient well to stimulate growth of mefeane-oxidizmg (mefeaiK*ropie)ofgamans. These organisms produce the sfcongoxidizmg agent (mpnooxygenase) needed for complete mineralization of TCE. As expected, methanotropic degradation of TCE was constrained to the sparging operation's radius of influence (approximately 60 feet) but vinyl chloride degradation was found to occur wherever oxygen was present (continued on page 4] ------- [continued'frontpage3] > -•, ' Methane injection was terminated in January 2001 because TCE concentrations had decreased substantially and numerical. modeling predicted that the benefit of additional injection was limited. - Both wells currently treat vinyl chloride by serving as aerobic biodegradation pathways and by enhancing volatilization. Air is injected f into the wells once every two weeks for 48 continuous hours "at a rate of 220 scfm in -the downgradient weH and 250 scfm in the side- gradient well. After 24 hours, nitrous" oxide and triethylphosphate'nutrients (0.048% and' -0.005% of total air/month, respectively) are injected in the downgradient well for 8 hours. Vinyl chloride concentrations have continued 40 decrease over the past year, with maximum concentrations during the first quarter of 2003 reaching 80 yg/L in ah, interior landfill monitoring well and 11 ugC'in apoint-of- compliance well at the base of theJandfill, XJroundrwater models predict that primary. contaminant concentrations, will not exceed ground-Water protection standards due'to ongoing physical and biologicat processes, 6f natufa^attenuatioa Since concentrations^ have decreased to-regulatory^ limits for this RC3SAfacility, plans are underway tok&pend 'operation'of the biospargmg'system^and.to continue grqund-watef monitoring for several years-. Nlaintenaace of the biosparging . system wiU continue-in the event monitoring results indicate th'at resumed operations are .warranted. Additional information regarding enhanced bioremediation and monitored natural attenuation at the,SRS SLF is available on-line at http://www.srs.gov/general/pubs/ capped sanitary l^landfill 1 North Contributed by David O. Ndffsinger. - We*stinghoiise*SdVannah River • "- "Compaq, LLC (803-952-7768 or - d.noffsiftser@srs.sov) and Karen M.' Adams 'U.'S. Department ofEnergy/SRS '(803-725-4648 or kgr-en-m-adams @ srs.eov J creek water table aquifer horizontal treatment well south of landfill Legend *• Water Flow Direction Figure 2. A conceptual model of factors affecting ground-water flow and contaminant. transport was developed for the SRS SLF ; Electrical Resistance Heating Pilot Conducted f or VOC Removal A pilot study was completed in January 2003 at the Silresim Superfund site in Lowell, MA, to evaluate the effectiveness of electrical resistance heating (ERH) technology in treating contaminated soil and ground water. The U.S. EPA/Region 1 and Army Corps of Engineers will use the pilot results to determine the feasibility and cost of implementing mis technology on a full-scale basis for remediation of the vadose and saturated zones. Concentrations of vapor extracted over three months of treatment indicated that an estimated 1,500 pounds of VOCs were removed from approximately 1,000 cubic yards of soil. As a result of past industrial waste reclaiming operations, the subsurface soil and ground water at this 5-acre site contain high concentrations of VOCs, including TCE,PCE, 1,1,1 -trichloroethane, methylene chloride, and BTEX. Pre-treatment sampling revealed extensive contamination with total VOC concentrations exceeding 800 mg/L in ground water and 1,000 mg/kg in soil. The geology consists of fill and fine sand extending to approximately 10 ft bgs with an approximate hydraulic conductivity of 3.9 x 104cm/sec. A varved clayey silt layer with an estimated hydraulic conductivity of 5.5xlO-5cm/sec exists at 10-30 feet bgs. Below the clayey silt is alayer of silty and very fine sand with an estimated hydraulic conductivity of 1.1 x 10^ cm/sec. The pilot was conducted in a 25-ft-diameter test cell with heating electrodes extending 40 ft bgs (Figure 3). The site was covered by a 40-by-40-ft cap consisting of a gravel vapor collection layer, a polyvinylidene fluoride membrane to protect thecap from chemical attack, 1.5-inch R-11 foam insulation to reduce heat loss to the surface, and a reinforced HOPE membrane for weather protection. Fourteen electrodes were used to deliver six-phase, 240-kW power into the subsurface. The electrodes were installed as six pairs in a hexagonal pattern. Each pan- consisted of a shallow electrode providing heat at 2-10 feet bgs and a deep electrode providing heat at 10-40 ft bgs. Two neutral electrode were installed at similar depths in the center of the hexagon. All electrodes doubled as vapor extraction wells to capture the liberated subsurface contaminated vapors. The electrodes consisted of vertically slotted carbon steel piping with graphite granules as conducting filter pack. Drop tubes were installed [continued on page 5j ------- [continued from page 4] in the wells of each shallow electrode and connected to the vapor extraction system to "slurp" water and maintain a constant water level. In addition, electrolyte drip lines were installed in the filter pack to maintain adequate moisture for electrical conduction. Power was delivered to each deep electrode through a parallel connection from its paired shallow electrode. The shallow electrodes drew approximately 20 amps of current, while the deep ones drew approximately 250 amps. The vapor collection system consisted of 4- inch CPVC headers with 114-inch, high- temperature, chemical-resistant hose connections to each electrode. Emitted vapor was directed sequentially to an air-water separator, a plate-and-frame heat exchanger/ condenser, a cyclone separator, three 8,000-lb vapor-phase carbon vessels in series, and a regenerative vacuum blower. The total vapor flow rate was approximately 300 scfin; of this, approximately 70% was attributed to the horizontal collection pipes located near the perimeter of the hexagon, 20% to the shallow electrodes, and 10% to the deep electrodes (as apressure relief for the saturated zone). Treated vapors were discharged through a 15-ft stack. A total of approximately 48,000 pounds of granular activated carbon was used for vapor treatment during the pilot project. Fourthermocouple strings were installed inside and immediately outside the electrode array; the interior strings were placed equidistant from the electrodes, where heating was least effective. The thermocouples (nine per string) were installed at 5-ft intervals to a depth of 45 feet Ground temperatures reached steam temperatures at a depth of approximately 40 feet, and increased to 115°C at 35 feet After eight weeks of heating, temperatures in the target interval for the subsurface treatment zone achieved boiling temperatures. Measurements of ambient vapor concentrations using field instruments indicated no uncontrolled vapor emission from the electrode array throughout the pilot test operations. Overall, soil conducted electricity at levels higher than anticipated, possibly due to the presence of buried metal waste. Minor stray electrical voltages were observed outside the [continued on page 6] Contact Us Technology News and Trends is on the NET! View, download, subscribe, and unsubscribe at: http://www.epa. gov/tio httpy/cluin.org Technology News and Trends welcomes readers' comments and contributions. Address correspondence to: Ann Eleanor Technology Innovation Office (5102G) U.S. Environmental Protection Agency Ariel Rios Building 1200 Pennsylvania Ave, NW Washington, DC 20460 Phone:703-603-7199 Fax:703-603-9135 ------- |