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[기술동향] [Water Service] 간척시설의 실증 프로젝트 계약
[Water Service] 간척시설의 실증 프로젝트 계약
물 재사용 전문회사인 Integrated Water Services가 150만 달러 규모의 건설 계약을 체결했다고 밝혔다. 이 계약은 샌디에고의 Ray Stoyer 매립 시설의 하루 380㎥의 직접 음용 가능한 재사용 실증 프로젝트이다.
이 실증 프로젝트는 시설의 생산량을 하루 7천579㎥에서 1만6천654㎥로 확장시키는 계획의 준비 단계이다.
샌디애고 기반의 Prdre 댐 지방 용수 지구는 샌티 강 유역의 대수층 재충전 프로젝트에 고품질로 처리된 재생수를 공급하기 위해 마이크로 여과기와 UF 기술을 도입하는 확장을 고려하고 있다. 확장을 위한 제안서의 설계 요구는 2016년에 광고되며, 확장은 2020년에 완공될 예정이다.
[원문내용]Integrated Water wins US$ 1.5 million demonstration project deal
Water reuse specialist, Integrated Water Services, has won a contract to build a US$ 1.5 million, 380 m³/d indirect potable reuse demonstration project at the Ray Stoyer Water Reclamation Facility in San Diego County, USA.
The demo project is part of preparations for a planned expansion of the facility output from 7,579 m³/d to 16,654 m³/d.
San Diego County-based Padre Dam Municipal Water District is currently considering the expansion, which will employ micro filtration and ultrafiltration technologies to serve the Santee Basin Aquifer Recharge Project with highly treated recycled water. A design request for proposals for the expansion could be advertised in 2016 and the expansion could be completed by 2020.
Meanwhile, consultant, Kennedy/Jenks is preparing a report on a proposal to up output at the water reclamation facility to 37,850 m³/d.[출처 = Desalination & Water Reuse / 2014년 10월 2일]
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[기술동향] [미국] 물 인프라에 투자하면 캘리포니아 시설이 가뭄 다루는 데 도움
[미국] 물 인프라에 투자하면 캘리포니아 시설이 가뭄 다루는 데 도움
캘리포니아 사전대책 시설인 Fitch Ratings의 새 보고서에 따르면, 물 인프라에 대한 장기적인 투자는 가뭄 기간 동안의 물 공급을 다루는 데 더 도움이 된다.
캘리포니아 주의 가장 큰 공공 수도 시설 다섯 개 중, Fresno와 Sacramento는 현재 겪고 있는 가뭄때문에 대체 수자원에 대해 가장 크게 압박을 받고 있다. Fresno가 지하수 과다펌핑으로 인해 가뭄과 관련되어 가장 취약한 것에 비해, Sacramento는 적은 지표수 흐름과 수도계량기처럼 기본적인 물관리 기술에 대해 적용이 느린 것으로 인해 많은 비용이 드는 상황이다.[원문내용]Water infrastructure investments help CA utilities deal with drought, report findsAccording to a new report by Fitch Ratings, California utilities that have made proactive, long-term investments in water infrastructure are better equipped to deal with water supply pressures during drought.Among five of the state\'s largest public water utilities, Fresno and Sacramento are most pressured for alternative water sources by the current severe drought. While Fresno faces overpumped groundwater and is most vulnerable to a drought-related downgrade, Sacramento is realizing the cost of heavy reliance on vulnerable surface water flows and tardy adoption of basic water conservation technology like water meters.\'When cities make long-term investments in water infrastructure, not every drought turns into a fire drill for conservation," said Kathy Masterson, senior director at Fitch Ratings. "The fact is that droughts are cyclical, and careful planning can help offset or delay some of the resulting stresses like water restrictions."Decades of previous planning have given cities like San Diego, Los Angeles and northern California\'s East Bay Municipal Utility District more certainty regarding their water supplies. Those just beginning to make infrastructure investments, like Sacramento and Fresno, may need to enforce strict conservation policies to prevent near-term water shortages.While the steep cost of necessary investments for supply redundancy or supply hardening may be undesirable to ratepayers, it can prevent water restrictions and significant rate impacts in the future.
[출처 = Water World / 2014년 10월 8일] -
[기술동향] [미국] 하수 PPCPs, 얕은 지하수 오염시킬 수 있다는 연구결과 발표
[미국] 하수 PPCPs, 얕은 지하수 오염시킬 수 있다는 연구결과 발표
미국 지질조사(USGS)에 의해 실시된 새 연구에 따르면 의약품, 그리고 처리된 지자체 하수로부터 나온 불순물들이 강으로 유입된 뒤에도 얕은 지하수를 타고 떠다닐 수 있다는 사실이 밝혀졌다. 이 조사는 아이오와 주의 Des Moines 시 주변의 하수가 많이 유입되는 작은 하천인 Fourmile Creek에서 실시됐다.
연구 샘플은 2012년 10월과 12월에 개울에서 채취됐다. 10월에 하수는 강물의 약 99%를 구성했고, 12월에는 약 71%를 구성했다.
[원문내용]
Wastewater PPCPs can contaminate shallow groundwater following release to streams, finds study
According to a new study conducted by the U.S. Geological Survey (USGS), pharmaceuticals and other contaminants from treated municipal wastewater are able to travel into shallow groundwater following their release to streams. The research was conducted at Fourmile Creek, a small, wastewater-dominated stream near Des Moines, Iowa.
Samples for the study were taken from the creek during the months of October and December of 2012. In October, the wastewater comprised about 99 percent of the stream\''s flow, whereas in December, the wastewater made up about 71 percent of the flow. During both months, Fourmile Creek experienced persistent dry conditions. The study showed that pharmaceuticals and other contaminants are most likely to contaminate adjacent shallow groundwater systems during dry conditions when wastewater contributes the greatest proportion to streamflow.
"Water level measurements obtained during this study clearly show that stream levels drive daily trends in groundwater levels," said Paul Bradley, the study\''s lead author. "Combined with the detection of pharmaceuticals in groundwater collected several meters away from the stream, these results demonstrate that addition of wastewater to this stream results in unintentional, directed transport of pharmaceuticals into shallow groundwater."
Samples from the stream and groundwater were analyzed for 110 pharmaceutical compounds, as well as other chemicals like personal care products and hormones. These compounds are able to move into the groundwater systems because they remain dissolved in the water, rather than attaching themselves to the sediments that filter other chemicals out as the water moves from the stream into adjacent groundwater. There were no sources of these pharmaceuticals to groundwater in the study reach other than municipal wastewater in the stream.
This study found that 48 and 61 different pharmaceuticals were present downstream of the wastewater discharge point during the two periods of study, with concentrations as high as 7,810 parts-per-trillion (specifically the chemical metformin, an anti-diabetic pharmaceutical). Correspondingly, between seven and 18 pharmaceuticals were present in groundwater at a distance of about 65 feet (20 meters) from the stream bank, with concentrations as high as 87 parts-per-trillion (specifically fexofenadine, an antihistamine pharmaceutical).
"This research has important implications for the application of bank filtration for indirect water reuse," said Bradley. Bank filtration is the engineered movement of water between surface waterbodies and wells located a short distance away on the streambank. Bank filtration is routinely used to pretreat surface water for drinking water supply (raw surface water moves from the stream to a shallow groundwater extraction well) or as a final polishing step for the release of treated wastewater (treated wastewater moves from infiltration wells or lagoons through the bank to the stream).
This study is part of a long-term effort to determine the fate and effects of contaminants of emerging concern and to provide water-resource managers with objective information that assists in the development of effective water management practices. More information on this study and other studies on contaminants of emerging concern can be found here.
[출처 = Water World / 2014년 9월 22일] -
[기술동향] [미국] VT 쓰레기매립지 슈퍼펀드 현장 처리방안에 대한 수정사항 발표
[미국] VT 쓰레기매립지 슈퍼펀드 현장 처리방안에 대한 수정사항 발표
환경보호국(EPA)가 BFI 로킹엄 쓰레기매립지 슈퍼펀드 현장에 대해 현재 진행 중인 처리방안의 주요 추천 수정사항을 제안했다. 이는 현장의 지하수를 정화하기 위해 늘어난 기간과, 오염된 물에 노출되는 것을 예방하기 위해 추가된 지하수 제한, 비소와 납의 오염물질 때문에 변경된 정화단계를 모두 포함한다.
EPA는 개선책이 이 두 금속물질에 대한 주와 연방의 표준을 변화하는 데 기초해 인류의 건강과 환경을 보호한다는 것을 보장하기 위해 이러한 측정을 진행하고 있다.
[원문내용]
EPA announces major modifications to ongoing VT landfill Superfund site remedy
The Environmental Protection Agency (EPA) has proposed major recommended modifications to the ongoing remedy of the BFI Rockingham Landfill Superfund Site (Site) in the city of Rockingham, Vt., that include an increased timeframe to cleanup Site groundwater, additional groundwater restrictions to prevent exposure to contaminated groundwater, and revised cleanup levels for two contaminants -- arsenic and lead.
EPA is carrying out these measures to ensure that the remedy remains protective of human health and the environment based on changes to the federal and state standards for these two metals. Further, the Agency will be accepting public comment on these recommended modifications from Sept. 11 to Sept. 25, 2014.
The Site is a 17-acre landfill located along U.S. Route 5 and adjacent to the Connecticut River. From 1968 until 1991, the landfill received residential, commercial and industrial solid and liquid wastes. Approximately 1.2 million cubic yards of solid waste were disposed in the landfill during its operation. The majority of wastes were placed in unlined landfill cells. In October 1989, the Site was included on the EPA National Priorities List (NPL).
The 1994 cleanup plan, also known as the Record of Decision, estimated that the groundwater restoration aspect of the cleanup would be complete in a 15-year timeframe. By the spring of 2009, however, long-term monitoring results indicated that Interim Groundwater Cleanup Levels would not be achieved in that timeframe. At EPA\'s request, consultants to BFI Waste Systems of North America, LLC undertook additional investigations of bedrock groundwater, which show Site groundwater will likely meet interim groundwater cleanup levels in 40 to 60 years.
[출처 = Water Wold / 2014년 9월 18일] -
[기술동향] [미국] 수압파쇄 정 가스 누출…지하수 오염
[미국] 수압파쇄 정 가스 누출…지하수 오염
오하이오 주립대학교과 로체스터대학레이저에너지 연구소, 다트머스 해군 사관학교, 스탠포드 대학교, 듀크대학교의 연구원들이 실시한 최근 연구의 결과, 수열 파쇄 부지의 케이싱 및 시멘트 우물 라이닝에 대한 향상된 건설 기준을 찾았다고 발표했다. 수열 파쇄 지역은 셰일가스 시추기술인 수열파쇄과 관련된 식수정에서 발생한 대부분의 자연 가스 오염의 원인이 된다.
연구팀은 어떻게 메탄이 지구 아래서 이동하는지 추적할 수 있는 새로운 지구화학적 방법을 고안했으며 이 연구는 펜실베니아와 텍사스 주에 위치한 8개의 오염된 식수정에서 확인됐다. 연구 결과 중 가장 중요한 것은 수평보링과 셰일 매장층의 수압파쇄 모두 자연가스 오염의 원인으로 보이지 않았다.
연구 책임자 Thomas Darrah는 " 많은 사례를 보면 의심의 여지없이 많은 자연 가스의 오염수준은 자연스럽게 발생한다. 하지만 일부의 경우, 오염에 대해 사람이 원인이 된다는 확실한 증거이기도 하다."고 설명했다. 이어 " 하지만 우리의 데이터는 오염이 발생했을 때 이 원인의 정의 열악한 케이싱과 접합으로 발생한다."고 제안하고 있다.
[원문내용]
Gas leaks from faulty fracking wells linked to groundwater contamination, finds study
Results from a new study conducted by a team led by a researcher at Ohio State University and researchers at Duke, Stanford, Dartmouth, and the University of Rochester, have found that improved construction standards for cement well linings and casings at hydraulic fracturing (fracking) sites is the likely source of most natural gas contamination in drinking water wells associated with fracking.The team recently devised a new method of geochemical forensics to trace how methane migrates under the earth. The study identified eight clusters of contaminated drinking water wells in the states of Pennsylvania and Texas. Most important among their findings is that neither horizontal drilling nor fracking of shale deposits seems to have caused any of the natural gas contamination.
"There is no question that in many instances, elevated levels of natural gas are naturally occurring, but in a subset of cases, there is also clear evidence that there were human causes for the contamination," said study leader Thomas Darrah, assistant professor of earth sciences at Ohio State. "However, our data suggests that where contamination occurs, it was caused by poor casing and cementing in the wells."
During fracking, water is pumped underground to break up shale at a depth far below the water table, he explained. The long vertical pipes that carry the resulting gas upward are encircled in cement to keep the natural gas from leaking out along the well. The study suggests that natural gas that has leaked into aquifers is the result of failures in the cement used in the well.
"Many of the leaks probably occur when natural gas travels up the outside of the borehole, potentially even thousands of feet, and is released directly into drinking water aquifers," said Robert Poreda, professor of geochemistry at the University of Rochester. Further, Avner Vengosh, professor of geochemistry and water quality at Duke, added, "These results appear to rule out the migration of methane up into drinking water aquifers from depth because of horizontal drilling or hydraulic fracturing, as some people feared."
The method that the researchers used to track the source of methane contamination relies on the basic physics of the noble gases (which happen to leak out along with the methane). Noble gases such as helium and neon are so called because they don\''t react much with other chemicals, although they mix with natural gas and can be transported with it.
That means that when they are released underground, they can flow long distances without getting waylaid by microbial activity or chemical reactions along the way. The only important variable is the atomic mass, which determines how the ratios of noble gases change as they tag along with migrating natural gas. These properties allow the researchers to determine the source of fugitive methane and the mechanism by which it was transported into drinking water aquifers.
The researchers were able to distinguish between the signatures of naturally-occurring methane and stray gas contamination from shale gas drill sites overlying the Marcellus shale in Pennsylvania and the Barnett shale in Texas. The researchers sampled water from the sites in 2012 and 2013. Sampling sites included wells where contamination had been debated previously; wells known to have naturally high level of methane and salts, which tend to co-occur in areas overlying shale gas deposits; and wells located both within and beyond a one-kilometer distance from drill sites.
[출처 =Water World / 2014년 9월 15일]
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