NATURAL RESOURCES AND THE ENVIRONMENT

Sustainable Management of California's Bay-Delta

Technician pretreating ground wheat straw for biofuel production, USDA Agricultural Research Service photo by Peggy Greb

California's Bay-Delta supplies water to agriculture and metropolitan areas in much of the state. Over time, the delta has been substantially modified to meet growing demands, and this has affected the delta's ecosystem and wildlife.

Sustainable Water and Environmental Management in the California Bay-Delta says that the state's simultaneous goals of attaining a reliable water supply for California and protecting and rehabilitating the delta's ecosystem have value, but better planning is required to identify how trade-offs between these two goals will be managed when water supplies are short. Failure to acknowledge the increasing likelihood of water scarcity in the area and craft plans and policies that address this has made delta water management more difficult than is necessary, the report says. The extensive physical and ecological changes to the delta over the last century make it impossible to restore the habitat to its pre-disturbance state.

Overall, moving toward environmental sustainability while continuing to supply the state with water will require careful decision making. Better definition and management of water scarcity, increased collaboration between the numerous agencies and organizations that oversee the delta, and strategies to mitigate environmental stressors that affect delta wildlife all will be needed. In addition, the report says, an assessment of the effects of climate change and projected sea-level rise is essential, along with a comprehensive review of water planning and management in anticipation of future environmental and water supply needs.

The National Research Council study was funded by the U.S. Department of the Interior.

Sea-Level Rise on the West Coast

Oregon coast, ©Ingram Publishing/Thinkstock

A warming planet triggered a rise in global sea levels during the 20th century, and projections suggest sea levels will rise at a higher rate over the next 100 years. California, Oregon, and Washington each have hundreds of miles of shoreline close to valuable infrastructure, development, and wetlands vulnerable to rising sea levels. The three states asked the National Research Council to assess how the region would be affected.

Sea-Level Rise for the Coasts of California, Oregon, and Washington: Past, Present, and Future projects that the sea level off most of California is expected to rise about 1 meter over the next century, an amount slightly higher than projected for global sea levels. Sea levels off Washington, Oregon, and northern California will likely rise less, about 60 centimeters over the same period of time. The report estimates a global sea-level rise of 50 to 140 centimeters by 2100, which is substantially higher than the United Nations Intergovernmental Panel on Climate Change's projection made in 2007.

With climate change, the number and duration of extreme storm surges and high waves are expected to escalate, and this, combined with sea-level rise, increases the risk of flooding, coastal erosion, and wetland loss, the report says. And extreme events such as a magnitude 8 or greater earthquake could raise sea level off Washington and Oregon much faster than the rates projected.

The National Research Council study was funded by the states of California, Washington, and Oregon; National Oceanic and Atmospheric Administration; U.S. Geological Survey; and U.S. Army Corps of Engineers.

Florida's Water Quality Rule

Florida Everglades, photo by Brian Call, National Park Service

Hundreds of waterways in Florida are contaminated by excess nutrients such as nitrogen and phosphorus, mainly from agricultural runoff. Florida manages its waterways by using "narrative" criteria, which use words to describe pollution limits. In 2009 the U.S. Environmental Protection Agency proposed adopting numeric criteria to establish limits on the concentrations of water pollutants in an effort to accelerate and standardize restoration efforts. The agency produced an economic analysis of the potential costs associated with this change.

Review of the EPA's Economic Analysis of Final Water Quality Standards for Nutrients for Lakes and Flowing Waters in Florida says that while EPA's approach to calculating the cost of the rule change was correct, the agency underestimated both the number of newly impaired waters and the mitigation costs for the stormwater, agricultural, septic system, and government sectors. In addition, the report finds significant uncertainty in how costs for municipal and industrial wastewater sectors were evaluated.

Many discrepancies in estimates by EPA and other stakeholders were due to different assumptions about the rule change's impact on actions taken over the water quality management cycle. The report offers a more comprehensive and explicit approach for analyzing how a rule would be implemented over time. It also notes that the costs of the rule change would be small relative to the total costs required to restore Florida's nutrient-impaired waters.

The National Research Council study was funded by the U.S. Environmental Protection Agency.

The Potential of Treated Wastewater

©iStockphoto/Thinkstock

Water is scarce in many parts of the world, and demand is expected to rise as population growth and climate change place additional stresses on supplies. In the U.S., many municipalities have started using another resource -- treated wastewater -- to irrigate golf courses and parks or provide industrial cooling water.

Reusing treated municipal wastewater for many different uses, including for drinking water, could significantly increase the nation's total available water resources, says Water Reuse: Potential for Expanding the Nation's Water Supply Through Reuse of Municipal Wastewater. New analyses suggest that the risk of exposure to certain microbial and chemical contaminants from potable wastewater reuse are about the same as, or in some cases less than, the risk posed by some existing water supplies.

Water reuse costs vary greatly from location to location depending on factors such as water quality requirements and treatment methods. Water reuse projects are generally more expensive than most water conservation options but less expensive than seawater desalination. Water authorities, however, should consider other costs and benefits in addition to monetary expenditures when assessing reuse projects, the report says.

Water reuse regulations differ by state, and many are not based on risk-assessment methods. Adjustments to the federal regulatory framework could help ensure a high level of public health protection, provide a consistent minimum level of protection across the nation, and increase public confidence in potable and non-potable water reuse.

The National Research Council study was funded by the U.S. Environmental Protection Agency, U.S. Bureau of Reclamation, National Science Foundation, National Water Research Institute, Centers for Disease Control and Prevention, Water Research Foundation, Orange County Water District, Orange County Sanitation District, Los Angeles Department of Water and Power, Irvine Ranch Water District, West Basin Water District, Inland Empire Utilities Agency, Metropolitan Water District of Southern California, Los Angeles County Sanitation Districts, and Monterey Regional Water Pollution Control Agency.

Rethinking Groundwater Cleanup

©Volker Steger/Science Source

Over the last three decades, federal and state agencies have spent billions of dollars to clean up contaminated groundwater beneath hazardous waste sites such as those at Superfund sites and military installations. U.S. Department of Defense sites make up approximately 3.4 percent of the total active remediation sites, with many of these presenting significant technical challenges and very high costs. DOD asked the National Research Council to examine the future of groundwater remediation efforts.

Meeting cleanup goals at the most challenging contaminated sites is unlikely for many decades, says Alternatives for Managing the Nation's Complex Contaminated Groundwater Sites. About 10 percent of the 126,000 DOD sites that require remediation across the U.S. is considered "complex," such that restoration to drinking water standards is unlikely to be achieved in the next 50 to 100 years due to technological limitations.

The estimated cost of complete cleanup at these complex sites ranges from $110 billion to $127 billion, but the figures for both the number of sites and costs are likely underestimates, the report says. The cost estimates do not account for technical barriers to complete cleanup at complex sites or the costs of cleanup at future sites where groundwater may become contaminated.

If cleanup efforts at a site reach a point where continued spending brings little or no reduction in risk prior to attaining drinking water standards, a re-evaluation of the site should occur. Earlier implementation of this assessment could result in cost savings, but funding will still be needed to maintain long-term management at these complex sites.

The National Research Council study was funded by the U.S. Army.

Sustainable Development of Algal Biofuels

scientist at Los Alamos National Laboratory engaged in algae research for biofuels production and other applications, LANL photo

As the U.S. strives to meet its energy security needs and reduce greenhouse gas emissions, biofuels have gained attention as possible domestic alternatives to petroleum-based fuels. Biofuels made from algae offer potential advantages due to algae's ability to grow on non-croplands in cultivation ponds or vessels of freshwater, salt water, or wastewater.

Sustainable Development of Algal Biofuels in the United States says that despite these advantages, scaling up the production of algal biofuels with current technologies and algal strains to meet even 5 percent of U.S. transportation fuel needs would place unsustainable demands on energy, water, and nutrients.

Though estimates vary by production method, large quantities of freshwater and nutrients such as nitrogen and phosphorus are required to produce algal biofuels, and the amount of land with the correct topography, climate, and proximity to water and nutrients required could be expensive to purchase. Transporting resources to cultivation facilities could cause additional energy consumption, and there are uncertainties in estimates of how much greenhouse gas is emitted in the production process

However, further research and development could lead to innovations for sustainable production of algal biofuels. The report proposes a framework for research that includes assessing sustainability throughout the supply chain, evaluating the cumulative impact of resource use or environmental effects, and performing cost-benefit analyses.

This National Research Council study was funded by the U.S. Department of Energy.