Hazy Futures: Projecting the local impacts of global warming is a stubborn challenge. But cities need answers fast

American Association for the Advancement of Science (AAAS) | June 5th, 2025

A wastewater treatment plant isn’t top on everyone’s sightseeing itinerary. But on a cloudless, breezy day in April, Agmed Weber, operations manager for the Walnut Cr

A wastewater treatment plant isn’t top on everyone’s sightseeing itinerary. But on a cloudless, breezy day in April, Agmed Weber, operations manager for the Walnut Creek plant—which handles more than half of the sewage here in Texas’s booming capital city—is an enthusiastic tour guide. He marvels at the foresight of those who built the jumbo plant a half-century ago, when Austin was a third of its current size. “They were really thinking about the future,” he says. Weber feels a similar pressure—to prepare for not only continued population growth, but also a hotter future. Austin is “in a tight space where we need to think ahead,” he says.

Healthy, Fair, and Profitable: A Win-Win Pesticide Policy

Pacific Institute | January 1st, 2002

A new report released by the Pacific Institute and the California Green Scissors project makes the case for changing the way pesticides are regulated in California. Acc

A new report released by the Pacific Institute and the California Green Scissors project makes the case for changing the way pesticides are regulated in California. According to the report, if California significantly increased its funding for sustainable agriculture — instead of just spending money to regulate pesticide usage — we could aid California farmers, improve the public health and save millions of dollars in associated costs.

Heavily polluted Tijuana River drives regional air quality crisis

American Association for the Advancement of Science (AAAS) | August 28th, 2025

Intense industrial and urban wastewater pollution has plagued the Tijuana River for decades, causing long-term closure of neighboring beaches. Rico et al. showed that sur

Intense industrial and urban wastewater pollution has plagued the Tijuana River for decades, causing long-term closure of neighboring beaches. Rico et al. showed that surging wastewater flows in the summer of 2024 enhanced water-to-air hydrogen sulfide (H2S) transfer at a turbulent hotspot, leading to nighttime atmospheric H2S peaks thousands of times greater than typical urban levels. This example makes it clear that poor water quality can drastically affect air quality—an observation with important implications for global waterways.

Helium isotope studies in the Mojave Desert, California: implications for groundwater chronology and regional seismicity

Chemical Geology (Elsevier) | November 7th, 2003

Hexavalent Chromium Maximum Contaminant Level (MCL) Standardized Regulatory Impact Assessment (SRIA)

California State Water Resources Control Board (SWRCB) | May 4th, 2023

The Division of Drinking Water (DDW) of the State Water Resources Control Board (State Water Board) is responsible for adopting drinking water standards. Primary drinking

The Division of Drinking Water (DDW) of the State Water Resources Control Board (State Water Board) is responsible for adopting drinking water standards. Primary drinking water standards, as defined in section 116275 of the California Safe Drinking Water Act (Health & Safety Code (HSC), div. 104, pt. 12, ch. 4, section 116270 et seq.), must be set in accordance with the requirements of HSC 116365. The purpose of the proposed regulation addressed in this Standardized Regulatory Impact Assessment (SRIA) is to adopt a primary drinking water standard for hexavalent chromium in drinking water consisting of a maximum contaminant level (MCL) and pertinent monitoring and reporting requirements. Consistent with title 1 of the California Code of Regulations (CCR), section 2003(a), the economic impact method used for the assessment was the Regional Input-Output Modeling System (RIMS II) developed by the U.S. Bureau of Economic Analysis (BEA).

High organofluorine concentrations in municipal wastewater affect downstream drinking water supplies for millions of Americans

National Academy of Sciences (NAS) | January 6th, 2025

Historical Ecology and Landscape Change in the Central Laguna de Santa Rosa

San Francisco Estuary Institute (SFEI) | March 1st, 2017

This study synthesizes a diverse array of data to examine the ecological patterns, ecosystem functions, and hydrology that characterized a central portion of the Laguna d

This study synthesizes a diverse array of data to examine the ecological patterns, ecosystem functions, and hydrology that characterized a central portion of the Laguna de Santa Rosa during the mid-19th century, and to analyze landscape changes over the past 150 years. The primary purpose of this study was to help guide restoration actions and other measures aimed at reducing nutrient loads within this portion of the Laguna de Santa Rosa watershed.

Historical Fresh Water and Salinity Conditions in the Western Sacramento-San Joaquin Delta and Suisun Bay

Contra Costa Water District (CCWD) | February 23rd, 2010

The watershed of the Sacramento–San Joaquin Delta (Delta) provides drinking water to more than 23 million Californians as well as irrigation water for millions of acres

The watershed of the Sacramento–San Joaquin Delta (Delta) provides drinking water to more than 23 million Californians as well as irrigation water for millions of acres of agriculture in the Central Valley. The Delta itself is a complex estuarine ecosystem, with populations of many native species now in serious decline. The Delta estuary as we know it began to form about 6,000 years ago, following the end of the last ice age. Because the estuary is connected to the Pacific Ocean through San Francisco Bay, seawater intrusion causes the salinity of Suisun Bay and the Delta to vary depending on hydrological conditions. This seawater intrusion into the Delta affects estuarine species as well as drinking water and irrigation water supplies. Successful restoration of the Delta ecosystem requires an understanding of the conditions under which native species evolved. Contra Costa Water District’s report on “Historical Fresh Water and Salinity Conditions in the Western Sacramento-San Joaquin Delta and Suisun Bay” presents a detailed review of more than 100 years of studies, monitoring data, scientific reports, and modeling analyses that establish an historical record of the salinity conditions in the Western Delta and Suisun Bay.

Historical Seawater Intrusion Map Pressure 180-Foot Aquifer - 500 mg/L or Greater Chloride Areas

Monterey County Water Resources Agency (MCWRA) | April 11th, 2018

History and Sources of Co-Occurring Pesticides in an Abstraction Well Unraveled by Age Distributions of Depth-Specific Groundwater Samples

American Chemical Society (ACS) | November 24th, 2019

When groundwater-based drinking water supply becomes contaminated, the timing and source of contamination are obvious questions. However, contaminants often have diffuse

When groundwater-based drinking water supply becomes contaminated, the timing and source of contamination are obvious questions. However, contaminants often have diffuse sources and different contaminants may have different sources even in a single groundwater well, making these questions complicated to answer. Age dating of groundwater has been used to reconstruct contaminant travel times to wells; however, critics have highlighted that groundwater flow is often complex with mixing of groundwater of different ages. In drinking water wells, where water is typically abstracted from a large depth interval, such mixing is even more problematic. We present a way to overcome some of the obstacles in identifying the source and age of contaminants in drinking water wells by combining depth-specific sampling with age tracer modeling, particle tracking simulations, geological characterization, and contaminant properties. This multitool approach was applied to a drinking water well, where bentazon and dichlorprop contamination was found to have different pollutant sources and release histories, even though both pesticides can be associated with the same land use. Bentazon was derived from recent application to a golf course, while dichlorprop was derived from agricultural use more than 30 years ago. The advantages, limitations, and pitfalls of the proposed course of action are then further discussed.