국가지하수정보센터
빅데이터플랫폼기술동향
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[기술동향] [미국] 대규모 담수화 프로젝트에 대한 경제학 전승
[미국] 대규모 담수화 프로젝트에 대한 경제학 전승
캘리포니아 헌팅턴 비치(Huntington Beach)의 하루 250Ml를 처리하는 해수담수화플랜트에서 사용하는 해저 흡입관은 최근 전문가의 보고서에 따르면 “합리적인 기간 내에 헌팅턴 비치에서 경제적으로 실행되지 못했다”는 평을 받고 있다 이번 연구 결과는 규제 승인이 중심이 되어 해저 기술과 관련해 Huntingdon 프로젝트를 위태롭게 할 수 있다.캘리포니아 해안위원회와 플랜트의 개발자에 의해 소집된 독립적인 과학기술 자문 패널(Independent Scientific Technical Advisory Panel)에 의하면 Poseidon Resources사는 해저 지하수 수집도관에 대한 두 가지의 기술 옵션이 기술적으로 가능할 것을 발견했다.
[원문내용]
Experts slam economics of seabed intake for giant US desalination project
A 250 Ml/d seawater desalination (SWRO) plant planned for Huntington Beach, California using sub seafloor intake pipes was "not economically viable at the Huntington Beach location within a reasonable time frame" according to a recent expert report. The findings could jeopardise the Huntingdon project because sub seafloor technology was pivotal to regulatory approval.
The Independent Scientific Technical Advisory Panel, convened by the California Coastal Commission and the plant developer, Poseidon Resources, found that two construction options for a seafloor infiltration gallery (SIG) were viable technically. But in its report it concluded that a SIG was "not economically viable at the Huntington Beach location within a reasonable time frame due to high capital costs and only modest reduction in annual operating costs."
The advisory panel said the economic viability of the technology at Huntingdon was "highly uncertain" and that it was "unlikely that the unit price for produced water from a SWRO plant with the SIG intake technology would find a buyer under current and likely future estimates of alternative waters sources through 2033."
The panel calculated that Poseidon\'s favoured open ocean intake would have a unit cost 40-50% less than the sub seabed technology. It proposed that Orange County Water District "might be willing to pay these water costs in 2018,"
A sub seafloor approach was favoured on environmental grounds by the coastal commission whose approval is required before construction can begin so the findings.
In 2013 the coastal commission concurred with environmentalists who, on the grounds of danger to marine life objected to an open-ocean intake system. Poseidon withdrew its coastal permit application that year after the commission said its approval for the project would require Poseidon to use subsurface pipes. Subsequently the commission and Poseidon jointly selected the advisory panel which has considered the economic and environmental feasibility of sub seabed intakes.
[출처 = Desalination & Water Reuse / 2015년 8월 18일] -
[기술동향] [Duke Energy] 포괄적인 지하수 평가보고 제출
[Duke Energy] 포괄적인 지하수 평가보고 제출
듀크에너지(Duke Energy)는 주에서 14 석탄 플랜트의 노스캐롤라이나의 자연자원환경국(North Carolina Department of Environment and Natural Resources, NCDENR)에 대한 포괄적인 지하수 평가보고를 제출하기 시작했다. 기업과 자연자원환경국은 재 웅덩이(ash basins)로 덮인 지하수를 보호할 지속적인 방법을 결정하기 위해 다른 정보와 함께 과학을 이용한 기술을 사용할 방침이다.
일반적으로 900개의 새로운 모니터링의 설치를 통해 데이터를 수집했으며, 주 전역에서 국가 규제기관에 수년동안 제공한 5천 개 이상의 토양 및 물 표본은 역사적 데이터와 일치한다.
[원문내용]
Duke Energy begins submitting comprehensive groundwater assessment reports
Duke Energy has begun submitting comprehensive groundwater assessments to the North Carolina Department of Environment and Natural Resources (NCDENR) for each of the 14 coal plants in the state. The company and NCDENR will use this science and engineering, along with other information, to determine how best to continue to protect groundwater as ash basins are closed.
Generally, the data gathered through the installation of about 900 new monitoring wells and more than 5,000 soil and water samples across the state have been consistent with historical data provided to state regulators over many years. The first three assessments address operations at the H.F. Lee Energy Complex (Goldsboro), L.V. Sutton Energy Complex (Wilmington) and W.H. Weatherspoon Plant (Lumberton).
While study continues, the assessments indicate:
- H.F. Lee : Groundwater near ash basins is flowing away from neighbors\'' private wells. Impacted groundwater has migrated off site in isolated areas where there are no private wells.
- Sutton : The company is addressing off-site groundwater impacts by partnering in 2013 with the local water utility to extend a new municipal water line currently underway and by installing 12 "interceptor" wells that will pump groundwater back to the plant. Private drinking water wells sampled by NCDENR to date show exceedances only for substances that are also naturally occurring and common in the region\''s soil.
- Weatherspoon : Groundwater near ash basins is flowing away from neighbors\'' private wells. The area of groundwater impact is confined to the ash basin footprint and the former coal pile area.
- Data demonstrate that water quality in the Cape Fear, Neuse and Lumber rivers has not been affected by ash basin operations.Comprehensive site assessments for Duke Energy\''s other 11 North Carolina facilities will be filed with regulators by mid-September, which is consistent with the requirements in the N.C. Coal Ash Management Act. In each case, an overview and executive summaries of these lengthy reports will be posted here.
The next phase of work includes additional sampling and computer modeling in the next 90 days to better understand how groundwater conditions are expected to change over time. Where groundwater impacts need to be addressed, the sampling results and modeling will inform the best engineering solutions to protect groundwater long term.
Duke Energy also has ash excavation in progress at three Carolinas coal plants (Asheville and Riverbend plants in North Carolina and W.S. Lee plant in South Carolina) and recently announced its recommendation to excavate an additional 12 basins in North Carolina for technical reasons unrelated to groundwater. It continues to study remaining basins in the state and will use this groundwater data and modeling to inform effective basin closure recommendations.
[출처 = Water World / 2015년 8월 10일] -
[기술동향] [미국] 빗물 관리 방법에서 침투성 포장 방식의 인기
[미국] 빗물 관리 방법에서 침투성 포장 방식의 인기
새 보고서에 따르면 저영향 개발 방식은 해당 장소의 자연 수문학을 모방한 소규모 방식을 이용해 빗물 관리 분야에서 현명한 접근 방식으로 인기를 얻고 있다. 빗물 유출에 대한 하나의 해결책은 투수성 포장이다. 이러한 투수성 포장 방식은 여과막, 도로 및 주차장에서 유출되는 빗물의 일부를 활용해 지하수의 표면에 침투시킨다.텍사스 A&M AgriLife Extension Service의 수자원 관리 전문가 Fouad Jaberd[ 의하면 댈러스 포트워스(Dallas-Fort Worth) 지역의 땅은 대부분 포장되어있거나 물침투에 있어 불투과성 구조물에 의해 덮여있는 상태이다.
[원문내용]
Permeable pavement gaining popularity as smart stormwater management approach
According to new reports, low-impact development is gaining popularity as a smarter approach to stormwater management using small-scale practices to mimic a site\'s natural hydrology.
One solution to controlling runoff is permeable pavement. This porous pavement filters and allows a portion of roadway or parking lot runoff to infiltrate the surface to recharge groundwater sources.
Much of the land in the Dallas-Fort Worth area, for example, is paved or covered by structures that are impervious to water penetration, according to Fouad Jaber, Texas A&M AgriLife Extension Service specialist in water resources management.
Because of this imperviousness, the typical filtration and purification process conducted by soil and plants is sidestepped, he said. As a result, bacteria, sediments, oil, grease, pesticides, and fertilizer nutrients from yards, roads and parking lots end up running off directly into the Trinity River watershed.
As such, the North Central Texas Council of Governments created a program to reduce runoff from land-use developments and to educate local governments on the benefits of permeable pavements.
Infrastructure such as sidewalks, bike paths and parking facilities constructed or retrofitted with permeable pavements in place ease the strain on drainage systems by diverting a portion of surface water to groundwater reserves.They are cost-effective because they reduce a development\'s dependence on swales (artificial dips or slopes in the surface designed to channel, filter and increase infiltration), retention ponds and other stormwater management tools.
[출처 = Water World / 2015년 8월 4일]
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[기술동향] [미국] 캘리포니아, 담수화 활성화에 대한 고민
[미국] 캘리포니아, 담수화 활성화에 대한 고민
캘리포니아의 모로베이(Morro Bay)는 현재 역삼투 해수담수화 플랜트의 운영 실태를 캘리포니아 해안 위원회(Coastal Commission)에 지속적으로 보고할 방침이다. 이 플랜트는 1992년 건축되어 지난 2000년에 플랜트 허가가 만료했으며, 가끔 비상시에 사용된 것을 제외한 것 외에는 작동하지 않았다.
모로베이는 물구입과 관련해 미국 정부에 연간 182만 달러를 지급하는 20년 계약을 체결했다. 올해는 도시 물수요의 97%를 공급의 나머지는 지하수 및 매장 보유량에서 충족하고 있다. Morrow city 기술자인 Rob Livick에 따르면, 국가와 계약이 만료된 시점인 7년 만에 도시는 새롭게 시작되지 않을 것으로 보이며, 담수화 플랜트는 그 때까지 적은 물을 구입하는 계약을 재협상한 상태이다.
[원문내용]
California city ponders desalination revival
California\''s city of Morro Bay is poised to apply to the state Coastal Commission to operate continually its currently idle reverse osmosis desalination plant. The city let its operating permit expire in 2000, and the plant - built in 1992 - has not operated since then except for occasional emergency use.
Morro Bay has a 20-year contract to buy water from the state, paying about US$1.82 million annually. This year, that supply met 97% of the city\''s water demand with the rest coming from groundwater and reserves. According to Morrow city engineer, Rob Livick, the contract with the state expires in seven years and the city will not restart the desalination plant until it has renegotiated the contract to purchase less water. The city is obliged to pay for the contracted state supply whether it uses it or not said Livick.
Livick said the city expected to start planning for its future water supply within a year and those plans will include the desalination plant : "Even though it\''s years out, the planning for a transition like this needs to start happening well in advance," Livick said. He said the plant produces water at less than two thirds the cost of the rate charged by the state
Morro Bay\''s city council will ultimately decide how to structure its water supply portfolio. "In the long term, the permit is important to what will likely be part of our long- term water supply strategy," said city manager, Dave Buckingham.
In the long term, the city may not be able to use desalination as a primary supply because of complications with groundwater and seawater. The city has rights to draw groundwater in Morro Valley, to meet about half of its annual demand but he groundwater has a high nitrate content.
Seawater desalination has other problems, including high concentrations of naturally occurring iron in the water that clogs the desalination system. One of its five saltwater wells is especially impacted with iron. The city is looking into newer filtration devices for its seawater treatment component that require less maintenance and extensive backwashing.
Under current drought conditions in the region the plant provides a more reliable water source than the state contracted water. Last year, Morro Bay received 5% of its state water allocation, and this year it collected 15%.
The city stores reserve water in the San Luis Reservoir, which it has used during the current drought. "I envision at some point in the future, splitting up our water sourcing differently," Livick said. "One possibility might be one-third reclaimed water from our new water reclamation facility, one-third state water and one-third desalination."
Buckingham said he was optimistic that a water reclamation facility, planned as part of a new sewage treatment plant, will be available to recharge the Morro Creek well water.
He said the state water contract could be relegated to an emergency backup, given the possibilities for increased use of well water and desalination. The new reclamation facility could provide a significant supply should the use of treated wastewater for potable use become allowed under proposed legislation.
The sources of the water for desalination treatment are five saltwater wells along the Embarcadero and seven wells used to treat brackish water in the lower Morro Valley using reverse osmosis. Buckingham said the city was in the "very, very early stage" of exploring a partnership with private companies to build and operate a new desalination facility at the old Morro Bay power station site.
[출처 = Desalination & Water Reuse / 2015년 7월 26일]
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[기술동향] [미국] USGS, 새로운 지하수 모델 통한 대수층의 이해
[미국] USGS, 새로운 지하수 모델 통한 대수층의 이해
미국지질협회(U.S. Geological Survey, USGS)와 샌안토니오워터시스템(San Antonio Water System, SAWS)의 새로운 지하수 흐름 모델의 개발 덕분에 샌안토니오 및 텍사스 에드워즈 고원의 대수층 전체에 물이 흐르는 방법에 대해 보다 이해하게 되었다.
애드워즈 고원의 대수층은 세계에서 가장 물이 풍부한 대수층 중 하나이며, 샌안토니오와 오스틴(Austin)지역에서 소비되는 식수의 50% 이상을 제공하며, 중남부 텍사스 지역에 주거·여가·산업·농업 등의 용수를 공급한다. 멸종위기에 처한 동물들 또한 지하수에 의해 보호된다.
[원문내용]
New USGS groundwater model offers better understanding of Edwards Aquifer
Thanks to a new groundwater flow model developed by the U.S. Geological Survey (USGS) in cooperation with San Antonio Water System (SAWS), scientists now have a better understanding of how water flows throughout the San Antonio, Texas, segment of the Edwards aquifer.
The Edwards aquifer is one of the most prolific aquifers in the world and provides more than 50 percent of the drinking water consumed in the San Antonio and Austin areas. The aquifer supplies water to south-central Texas for residential, recreational, industrial, and agricultural uses. Several endangered and threatened species are also sustained by groundwater discharged at Comal, San Marcos and Barton Springs.
The focus of the new USGS model is to simulate the interaction between fresh water and saline (salt) water and where the two mix, called the brackish-water transition zone. Model results indicate that effects on fresh water during a severe drought, such as the drought-of-record during 1950-56, would be minor.
This model improves on a previous USGS model that did not include analysis of the transition or saline zones. While this new model is capable of making predictions of spring flow, salinity concentrations and water levels in nearby wells, the reliability of these predictions are also measured through use of a tool known as uncertainty analysis, which few groundwater modeling studies currently provide.
The model, coupled with uncertainty analysis, improves understanding of the potential effects of severe drought on the movement of water within and between the different water-quality zones. The full USGS report on the model is available here.
"While the model shows little potential for movement of brackish water into fresh water, the research suggests there is a need for an improved understanding of some parts of the Edwards aquifer flow system," said USGS scientist Linzy Brakefield. "Better knowledge of how the aquifer is recharged and the relationship between recharge, pumping and spring flow is needed."
[출처 = Water World / 2015년 7월 23일]
※ 본 정보는 국가과학기술정보센터(NDSL)에서 제공됩니다.
