当干旱的西方国家观看其水源的字面意义上，加利福尼亚正在深入挖掘最基本的资源：地下水。
Amid a worsening drought scorching much of the western U.S., California’s numerous and varied potential drinking water sources are becoming unusable or, when purchased from Colorado or other districts, too costly. As reservoirs, rivers and washes dry out, state water resource administrators are boosting use of alternative supplies to ensure water keeps flowing.
PARCHED |加利福尼亚州的水资源部说，大型摩根大片影响了该州的每个地区。创纪录的干燥条件（包括减少融雪，现在都延伸到美国西部的大部分地区
Groundwater is the “abandoned child of the water system because we have not been very meticulous in the way we gathered data or managed or protected it,” says Newsha Ajami, chief development officer for environmental research at Lawrence Berkeley Lab in Berkeley, Calif., and a longtime state drought expert.
但是，由于各种原因，更多地依赖地下水是有问题的。
Many groundwater wells—not monitored or managed until California enacted the Sustainable Groundwater Management Act in 2014—have simply been overdrawn.
Moreover, it was common practice during the 1940s and 1950s for industrial facilities, manufacturers and even dry-cleaners to dump chemicals and waste underground, leaving a legacy of pollution that renders some groundwater undrinkable.
Los Angeles is able only to consistently draw from 41 of 115 wells in the San Fernando Basin, a collection of regional underground aquifers that currently provide about 10% of city water supply. This has caused a 50% reduction in its historical groundwater supply. But the LA Dept. of Water and Power says the basin has the potential to provide as much as 21% of city water.
As a result, the department is working with federal and state officials, potentially responsible polluted site owners and a slew of engineering and construction firms on multiple remediation projects to return a more significant portion of groundwater supply to the drinking water system. Concentrated in the San Fernando Valley, these projects are using a combination of granular activated carbon tanks coupled with ultraviolet advanced oxidation when needed to clean up pollutants that have remained in the basins for decades.
The California Water Board says that hundreds of drinking water wells throughout the state have been contaminated. Not all can feasibly be remediated, says board member Sean Maguire. California now has a statewide effort underway to map all high- and medium-priority groundwater basins.
州水资源控制委员会成员肖恩·马奎尔（Sean Maguire）是土木工程师兼前顾问，他说，该部门一直是改造水的“真正领导者”，这是以前不受限制地进入城市水资源组合中的重要部分。
The U.S. Environmental Protection Agency established four Superfund sites within the valley in the mid-1980s, and efforts to identify responsible parties and remediate the groundwater basin have continued since then.
Some toxics, mainly detritus from manufacturing facilities that provided parts for aircraft, include a veritable alphabet soup of volatile organic compounds (VOCs), including trichloroethytlene, perchloroethylene, petroleum compounds and heavy metals.
同样存在的是1,4二恶英，通常在油漆剥离产品中发现，以及六价铬，它们既天然存在又包含在某些消费者和工业产品中，例如涂料和塑料。这些化学物质中的许多化学物质的数量足够大，除非经过处理，否则水不能安全饮用。
Complex Sites
Efforts to clean up contaminated groundwater sites have been complicated by the discovery of additional VOCs as well as by changing geological conditions that have caused a plume of contaminants to spread to new areas.
狭窄的区域|One remediation project is squeezed into a city block in a residential North Hollywood neighborhood. The construction crew has had to make adjustments, such as storing materials offsite, to work efficiently onsite.
阿贾米说：“人们没有意识到这些[地下水]盆地在许多不同的地理和管辖范围内都如此之大。”“人们将它们用于不同的目的。因此，确保每个使用这些盆地的人都注意到他们如何使用它们来确保他们不会过度使用它们或以不同的方式稀释它们，这一点非常重要。”她补充说，由于羽毛并不总是留在一个地方，因此人们可能会在远离原始污染物发生的地方受到影响。
狭窄的区域|The UV treatment facility at North Hollywood.
The LA Dept. of Water and Power negotiated settlements with Lockheed Martin and Honeywell in 2018 and 2019, respectively, that require the manufacturers to pay for cleanup of regional groundwater Superfund sites containing Cold War-era pollution.
In 2021, the department negotiated a second settlement with Honeywell to expedite work. Together, the agreements could generate more than 5 billion gallons of drinking water from groundwater annually for the next several decades, department officials say. EPA is overseeing the work at these sites, which is ongoing.
18luck官网正在进行的项目
The department has initiated construction projects to remediate three sites within the basin that collectively comprise the San Fernando Groundwater Remediation project: North Hollywood West, North Hollywood Central and Tujunga Well Field. The latter is located in the eastern basin, closer to the rim of the San Gabriel Mountains.
EPA now is contemplating a fourth site in the basin’s southern well fields, depending on the outcome of an ongoing remedial investigation.
该部门正在监督工作，以遵守联邦框架，以协调对危险废物清理的响应。该部门说，目前正在建设的三个站点实施的临时响应行动是个人补救调查和可行性研究的结果。
The total cost of the three projects already under construction is set to top $700 million, but may be higher if a fourth treatment facility is built in the southern well fields near Pollock.
HEAVY LIFT |At the North Hollywood, Calif., project site (above), the construction crew opted to use one large crane that could be placed in a central location, rather than multiple smaller cranes.
The department has received about $309.8 million in grant funds through California’s Proposition I initiative, a 2014 voter bond measure that authorizes the state water control board to fund up to 50% of major water infrastructure projects. Department consultant Hazen & Sawyer developed the remedial plan for the North Hollywood West facility, which will treat 16,000 acre-ft annually. Agency employees are completing construction work.
For the other two sites now being built—North Hollywood Central, with an annual treatment capacity of 28,000 acre-ft, and Tujunga Well Field, with annual treatment capacity of 43,000 acre-ft—the department opted to use progressive design-build. Kiewit is the prime contractor, and Stantec is engineer. Design work finished in March 2021, with construction set to wrap up by summer 2023.
北好莱坞中央和图洪加项目使用类似的方法来治疗被污染的井，尽管地理区域有所不同。18luck官网两者都使用颗粒状的活性碳罐进行挥发性有机化合物，该技术和紫外线氧化剂用于被T1,4二恶英污染的井。在将氯，氟化物和氨的组合使用到饮用水分配系统之前，使用氯，氟化物和氨的组合对所有处理过的水进行消毒。
狭窄的空间
虽然Tujunga遗址占地数英亩，但北好莱坞地点只是一个150英尺x 130英尺的城市街区，周围环绕着直到最近才居住的房屋。北好莱坞遗址的Kiewit项目经理Blake DePaola说：“在这里，治疗列车和技术与Tujunga相同。“我们的占地面积要减少得多。”他说，但是，较小的占地面积需要相当大的协调和后勤计划，而没有存储设备和材料的空间。
Working directly adjacent to residential properties presented another challenge at North Hollywood, DePaola says. Although the water department was able to purchase most properties closest to the treatment facility through a buyout program to be able to build all the structures that were needed for the project, the rapid rise of COVID-19 and ensuing eviction moratoriums presented added hurdles, DePaola says.
盆地地下水补救项目的部门土木工程师兼设计经理Jose Rubalcava说，交付方法允许施工按计划进行。他说：“我们不必等到设计完全完成，然后出价，然后将其授予承包商。”让承包商提早加入该项目的整体设计，并使您能够更好地设计和建筑团队合作。
Diversifying Portfolios in Face of Climate Change
GREEN FUTURE |洛杉矶市长埃里克·加塞蒂（Eric Garcetti）（顶部照片，举行标志）要求该市的100％废水在2035年回收。
Beyond groundwater, California is ramping up programs to recycle water supplies for drinking, aquifer replenishment and agricultural uses. The Los Angeles Dept. of Water and Power and LA Sanitation and Environment have developed an ambitious plan to achieve Mayor Eric Garcetti’s 2019 Green New Deal goal to recycle 100% of available wastewater for beneficial reuse in Los Angeles by 2035.
The $16.8-billion program, called Operation NEXT, includes multiple projects, but at its heart is the retrofit of the Hyperion water reclamation facility with advanced treatment processes to produce 217 million gallons per day (mgd) of purified recycled water. The existing plant treats an average daily flow of 260 mgd to secondary treatment standards, with about 27% of that used for irrigation and other non-potable uses.
据下一项运营经理拉斐尔·维拉加斯（Rafael Villegas）称，该计划的某些版本已经存在了将近20年。但是直到最近，它才进步，这是由于气候变化的加剧影响和对当地水源的更多需求所推动的。
The department is partnering with other agencies to conduct pilot studies and demonstration projects to evaluate how membrane bioreactors, biological activated carbon and other technologies perform in producing drinkable recycled water.
由于该州目前没有直接饮用品再利用的法规，因此加利福尼亚州正在进行这些试点研究和示威项目，以帮助“告知监管过程”，当时预计2023年某个时候将发布规则。18luck官网
维拉加斯说，对全面项目的水和卫生部门和其他合作伙伴将对“可以和不能批准的东西”有更好的感觉。18luck官网
The water department recently hired Jacobs to evaluate its pilot projects and develop an Operation NEXT master plan. Rich Nagel, a Jacobs vice president, notes that getting the mix of technologies right is important. Los Angeles “is looking at a combination of indirect and direct potable … so what is the right treatment for the purpose? Not overtreating, or undertreating, but [finding] the right level.”
Desalination Option
At the same time, desalination continues to be an option, or at least a consideration, although the California Coastal Commission’s rejection last month of a new proposed Poseidon facility last month was a blow to advocates. The firm has a $900-million operating plant in Carlsbad. But other smaller desalination facilities have been built, including one in Santa Barbara. Another is being considered in the Doheny Beach area outside of Los Angeles.
海水淡化“绝对可以portfo的一部分lio in California,” says Newsha Ajami, chief development officer for environmental research at Lawrence Berkeley Lab in Berkeley, Calif. “But is there a way that we can do this in an environmentally thoughtful way” when there is sufficient demand for it? she asks, noting that “there are still so many opportunities to reuse water multiple times.”
维拉加斯认为，无论采用什么技术，无论采用什么技术，都必须进行范式转变。未来几年将挑战水机构对水的更具创造力的思考。历史悠久的树木数据显示，在过去的2000年中，加利福尼亚的两次主要巨型群落。一个持续了120年，另一个持续了70年。
Although it is unknown how long the current drought will last, climate change and rising population levels will only exacerbate pressure on existing systems and infrastructure, according to Villegas. “The model we have for water supply today—we’re going to have to revisit that and think differently about it,” he points out. “How does an organization change to get itself ready to be able to take on a program of this size considering everything else that we already do?”
By Pam McFarland
Keeping on Track
Because of deadlines associated with the Prop 1 funding, Stantec delivered the design through a series of packages. This enabled Kiewit to start and complete work sooner, says Mike Watson, a senior vice president and major projects lead in Stantec’s water group. The firm provided separate packages for each site, and within those, developed 27 separate design packages to provide Kiewit more flexibility in planning and building treatment facilities and related infrastructure. He says the work “could not have been done” otherwise in the time allowed, with supply-chain and COVID-19 related constraints.
该部门预计将能够在北好莱坞遗址拆除附近的物业。但是由于大流行和其他情况，项目团队无法在计划中找到紫外线治疗过程。相反，它安装了现有的化学消毒单元所在的系统，并建立了临时的化学消毒系统以保持设施的运行。
At the Tujunga site, Kiewit drastically reduced the time the wells would be out of service—to just six weeks—by adding a 30-in.-dia pipe to convey about 27 million gallons per day of water from three wells without any contamination to the water distribution system, says Daron Toll, Kiewit project manager at the Tujunga site.
Originally, the construction team would have had to close off the water supply for the project’s entire duration—nearly two years to allow for the wells and associated infrastructure to be tied into the plant, and for treatment systems testing and commissioning. But with three non-contaminated wells, that plan was not palatable, he says. Crews added the pipe to allow water from non-contaminated wells to bypass the new treatment trains and flow into disinfection and then the water distribution system.
超越洛杉矶
Groundwater contamination extends beyond the San Fernando Valley basin, with hundreds of wells throughout California thought to be contaminated.
But with pumping and treating contaminated groundwater a costly endeavor, Maguire of the state water control board says some wells are simply too contaminated to treat. “It’s really a case-by-case scenario,” he says. “Is it too hot to touch, or is it [a site] that we can address and rely on in the near term as drinking water or for agricultural supply?”
Preventing Well Depletion
Many groundwater wells have also been overdrawn. The state’s 2014 sustainable groundwater law prevents overreliance on the same wells to the point of depletion. It requires agencies dependent on high- and medium-priority basins in California to develop plans for how best to manage their groundwater resources.
Under the law, the groundwater-dependent agencies must be able to recharge as much as they pump within 20 years. According to the Water Control Board, bringing pumping and recharging into balance will create a “drought buffer” during dry periods. “Before [the law], groundwater usage was basically the Wild West. You could pump it and use it and you didn’t have to tell anybody about it,” says Steve Stuart, a principal hydrogeologist at Encinitas, Calif.-based consulting firm Dudek.
DRINKABLE |Treated groundwater at the sites will go through disinfection with chlorine, ammonia and fluoride before being pumped into the drinking water distribution system
The firm was involved in early discussions related to the groundwater management law, and wrote nine sustainability plans for basins in southern California, he says, adding that some of the plans could prove controversial and even be litigated because they place limits on how much water can be drawn from groundwater sources, and by whom.
2021年6月和11月，州水资源部发布了其对2020年42项计划中的前六个计划的评估，其余的则于1月发布。已获得批准的计划可以继续执行。
获得更好的理解改变geological conditions in the groundwater basins, California is mapping them using drones and helicopters equipped with airborne electromagnetic technology. Building on work begun at Stanford University, the water resources agency says it is collecting data to develop continuous images of large aquifers, which will provide a standardized dataset to implement the law.
这些数据还将帮助州和地方水机构确定潜在的盆地，在这些盆地中可以进行其他补给或补给项目。18luck官网
资金机制
More than 32% of non-petroleum-contaminated groundwater sites in California are not being addressed because there is no responsible party linked to the pollution, or that entity or entities cannot pay for the cleanup, according to California’s water board.
但是，该州的某些地下水补救工作现在可能通过去年11月制定的《联邦基础设施投资和就业法》的资金加速。它为水和废水基础设施分配了550亿美元，其中包括与per和多氟烷基物质（PFAS）相关的补救措施的100亿美元。在加利福尼亚的地下水井中发现了一些PFAS化学品。
The infrastructure funding law also significantly boosts funds available through state revolving loan programs.
Additionally, a variety of state and local programs exist to support new infrastructure projects, including the Site Cleanup Subaccount program, known as SCAP, which provides grants to sites that pose an immediate risk to a community.
Community Support
环保团体支持清理工作。倡导组织加利福尼亚州加州水委员会联合主席Charming Evelyn表示，塞拉俱乐部已主张在地方和州一级的资金来支持圣费尔南多盆地清理计划等。她认为：“我们是清理地下水并将其作为当地来源重新将其重复的主要支持者……[我们提倡]水机构获得他们保持供水系统清洁所需的资金。”
Of contaminated sites not being addressed, nearly half are located in disadvantaged, underserved or rural communities, the water board says. A continuing concern is that smaller agencies may not have the resources or technical expertise to launch major capital programs.
A small agency that may serve only 2,000 people “cannot raise rates to cover the costs” for the work that is needed, Evelyn says.
Also, some of the people most harmed by groundwater contamination are indigenous or people of color who live in under-resourced areas, she says. Smaller or disadvantaged communities “should be at the front of the line to make sure they get the money that they need,” Evelyn adds. “Unfortunately, this is not the way that it works. So it’s a scramble.”
