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Onsite wastewater treatment systems (OWTSs), such as septic systems, are widely used in the United States, with 16.4% of households relying on them. OWTSs process approximately 4 billion gallons of wastewater per day, yet only about half is safely treated. Identifying factors contributing to impaired functionality is crucial for developing effective management and monitoring strategies and protecting environmental and human health. This study uses a machine learning approach and a unique data set from Athens-Clarke County, Georgia, to predict OWTS failures based on environmental and system-specific variables. The three main predictors of impaired OWTS function were the number of bedrooms (25.4%), height above stream (18.6%), and system age (16.2%), with both older and younger systems prone to failure. Our findings suggest there is a need to reevaluate construction guidelines for effective tank and drainfield sizing, placement, and construction, and our findings indicate that additional training for permitters, installers, and homeowners may be beneficial. Our work demonstrates the power of using machine learning to assess OWTS function, which can better enable local governments and environment managers to identify areas in need of infrastructure and educational investment with limited data and highlights the data types that local jurisdictions should prioritize for collection. 

Abstract Studies of annual patterns of ecosystem metabolism in rivers have primarily been conducted in temperate ecosystems, and little is known about metabolic regimes of tropical rivers. We estimated ecosystem metabolism in four nonwadeable rivers in southern México that varied in size and the extent of human disturbance. The smaller rivers with limited human disturbance showed reduced gross primary production (GPP; 1.0 and 1.7 g O₂m⁻² d⁻¹), ecosystem respiration (ER; − 1.9 g O₂m⁻²d⁻¹), and net ecosystem production (NEP) approaching autotrophy (− 0. 8 and − 0.3 g O₂m⁻²d⁻¹) relative to rivers draining larger, more disturbed catchments (GPP, 1.2 and 2.7 g O₂m⁻²d⁻¹; ER, − 5.7 and − 6.9 g O₂m⁻²d⁻¹; NEP, − 3.8 and − 3.7 g O₂m⁻²d⁻¹). In all rivers, GPP and ER varied seasonally with discharge. The smaller rivers exhibited a distinct pattern of greater and sustained GPP during periods of low discharge, a seasonal metabolic regime we describe as “flow decline.” In general, process–discharge relationships exhibited thresholds, with an initial decline in GPP and ER, with increasing discharge and an increase in ER at higher flows. Relative to larger and more disturbed watersheds, smaller rivers showed a more constrained metabolic fingerprint. Annual NEP (− 1033 and − 641 g C m⁻² yr⁻¹) in the larger rivers was more negative than the global average, supporting evidence from other studies that tropical rivers are greater contributors to CO²emissions than temperate ecosystems. Our study indicates that hydrological seasonality is a major driver of metabolism in tropical rivers. 

Novel in their scope and intensity, human‐mediated changes in genetic diversity through directed gene transfer technologies and longer standing human‐driven selective pressures, such as land‐use change, species introductions, mass extinctions, and broad application of antibiotics, are combining to reorganize mechanisms of evolution. The evolutionary consequences of anthropogenic change can be observed across levels of biological organization and are influencing the rate of micro‐ and macroevolutionary changes, as well as feedback among them. This may have large‐scale effects on the provisioning of ecosystem services, food security, and human health. Here, we summarize several of the ecological implications of human modification of evolutionary dynamics, focusing specifically on emerging molecular technologies, to highlight some of the challenges in predicting subsequent changes in the world’s ecosystems. 

Abstract Rapidly growing cities along the Interstate‐85 corridor from Atlanta, GA, to Raleigh, NC, rely on small rivers for water supply and waste assimilation. These rivers share commonalities including water supply stress during droughts, seasonally low flows for wastewater dilution, increasing drought and precipitation extremes, downstream eutrophication issues, and high regional aquatic diversity. Further challenges include rapid growth; sprawl that exacerbates water quality and infrastructure issues; water infrastructure that spans numerous counties and municipalities; and large numbers of septic systems. Holistic multi‐jurisdiction cooperative water resource planning along with policy and infrastructure modifications is necessary to adapt to population growth and climate. We propose six actions to improve water infrastructure resilience: increase water‐use efficiency by municipal, industrial, agricultural, and thermoelectric power sectors; adopt indirect potable reuse or closed loop systems; allow for water sharing during droughts but regulate inter‐basin transfers to protect aquatic ecosystems; increase nutrient recovery and reduce discharges of carbon and nutrients in effluents; employ green infrastructure and better stormwater management to reduce nonpoint pollutant loadings and mitigate urban heat island effects; and apply the CRIDA framework to incorporate climate and hydrologic uncertainty into water planning.