Forecasting freshwater cyanobacterial harmful algal blooms for Sentinel-3 satellite resolved U.S. lakes and reservoirs.

This forecasting approach may be useful for water managers and associated public health managers to predict near-term future high-risk cyanobacterial harmful algal blooms (cyanoHAB) occurrence. Freshwater cyanoHABs may grow to excessive concentrations and cause human, animal, and environmental health concerns in lakes and reservoirs. Knowledge of the timing and location of cyanoHAB events is important for water quality management of recreational and drinking water systems. No quantitative tool exists to forecast cyanoHABs across broad geographic scales and at regular intervals. Publicly available satellite monitoring has proven effective in detecting cyanobacteria biomass near-real time within the United States. Weekly cyanobacteria abundance was quantified from the Ocean and Land Colour Instrument (OLCI) onboard the Sentinel-3 satellite as the response variable. An Integrated Nested Laplace Approximation (INLA) hierarchical Bayesian spatiotemporal model was applied to forecast World Health Organization (WHO) recreation Alert Level 1 exceedance >12 µg L-1 chlorophyll-a with cyanobacteria dominance for 2192 satellite resolved lakes in the United States across nine climate zones. The INLA model was compared against support vector classifier and random forest machine learning models; and Dense Neural Network, Long Short-Term Memory (LSTM), Recurrent Neural Network (RNN), and Gneural Network (GNU) neural network models. Predictors were limited to data sources relevant to cyanobacterial growth, readily available on a weekly basis, and at the national scale for operational forecasting. Relevant predictors included water surface temperature, precipitation, and lake geomorphology. Overall, the INLA model outperformed the machine learning and neural network models with prediction accuracy of 90% with 88% sensitivity, 91% specificity, and 49% precision as demonstrated by training the model with data from 2017 through 2020 and independently assessing predictions with data from the 2021 calendar year. The probability of true positive responses was greater than false positive responses and the probability of true negative responses was less than false negative responses. This indicated the model correctly assigned lower probabilities of events when they didn't exceed the WHO Alert Level 1 threshold and assigned higher probabilities when events did exceed the threshold. The INLA model was robust to missing data and unbalanced sampling between waterbodies.

Plasma and Skin Per- and Polyfluoroalkyl Substance (PFAS) Levels in Dairy Cattle with Lifetime Exposures to PFAS-Contaminated Drinking Water and Feed.

Plasma and ear notch samples were removed from 164 Holstein cows and heifers, which had lifetime exposures to per- and polyfluoroalkyl substances (PFAS) through consumption of contaminated feed and water sources. A suite of nine PFAS including five perfluoroalkyl carboxylic acids (PFCA) and four perfluoroalkyl sulfonic acids (PFSA) was quantified in plasma and ear notch samples by liquid chromatography-mass spectrometry. Bioaccumulation of four- to nine-carbon PFCAs did not occur in plasma or skin, but PFSAs longer than four carbons accumulated in both plasma and skin. Exposure periods of at least 1 year were necessary for PFSAs to reach steady-state concentrations in plasma. Neither parity (P = 0.76) nor lactation status (P = 0.30) affected total PFSA concentrations in mature cow plasma. In contrast, lactation status greatly affected (P < 0.0001) total PFSA concentrations in ear notch samples. Skin samples could be used for biomonitoring purposes in instances when on-farm blood collection and plasma preparation are not practical.

Holistic Sustainability Assessment of Riparian Buffer Designs: Evaluation of Alternative Buffer Policy Scenarios Integrating Stream Water Quality and Costs.

Riparian buffer zones (RBZs) have been shown to be effective best management practices (BMPs) in controlling non-point source pollutants in waterbodies. However, the holistic sustainability assessment of individual RBZ designs is lacking. We present a methodology for evaluating the holistic sustainability of RBZ policy scenarios by integrating environmental and economic indicators simulated in three watersheds in the southeastern USA. We developed three unique sets of 40, 32, and 48 RBZ policy scenarios as decision management objectives (DMOs), respectively, in Back Creek, Sycamore Creek, and Greens Mill Run watersheds (Virginia and North Carolina) by combining the RBZ-widths with vegetation types (grass, urban, naturalized, wildlife, three-zone forest, and two-zone forest). We adapted the RBZ-hydrologic and water quality system assessment data of instream water quality parameters (dissolved oxygen, total phosphorus, total nitrogen, total suspended solids-sediment and biochemical oxygen demand) as environmental indicators, recently published by U.S. EPA. We calculated 20-year net present value costs as economic indicators using the RBZ's establishment, maintenance, and opportunity costs data published by the Natural Resources Conservation Service. The mean normalized net present value costs varied by DMOs ranging from 4% (grass RBZ-1.9 m) to 500% (wildlife RBZ-91.4 m) across all watersheds, due primarily to the width and the opportunity costs. The mean normalized environmental indicators varied by watersheds, with the largest change in total nitrogen due to urban RBZs in Back Creek (60-95%), Sycamore Creek (37-91%), and Greens Mill (52-93%). The holistic sustainability assessments revealed the least to most sustainable DMOs for each watershed, from least sustainable wildlife RBZ (score of 0.54), three-zone forest RBZ (0.32), and three-zone forest RBZ (0.62), respectively, for Back Creek, Sycamore Creek, and Greens Mill, to most sustainable urban RBZ (1.00) for all watersheds.

Catchment scale runoff time-series generation and validation using statistical models for the Continental United States.

We developed statistical models to generate runoff time-series at National Hydrography Dataset Plus Version 2 (NHDPlusV2) catchment scale for the Continental United States (CONUS). The models use Normalized Difference Vegetation Index (NDVI) based Curve Number (CN) to generate initial runoff time-series which then is corrected using statistical models to improve accuracy. We used the North American Land Data Assimilation System 2 (NLDAS-2) catchment scale runoff time-series as the reference data for model training and validation. We used 17 years of 16-day, 250-m resolution NDVI data as a proxy for hydrologic conditions during a representative year to calculate 23 NDVI based-CN (NDVI-CN) values for each of 2.65 million NHDPlusV2 catchments for the Contiguous U.S. To maximize predictive accuracy while avoiding optimistically biased model validation results, we developed a spatio-temporal cross-validation framework for estimating, selecting, and validating the statistical correction models. We found that in many of the physiographic sections comprising CONUS, even simple linear regression models were highly effective at correcting NDVI-CN runoff to achieve Nash-Sutcliffe Efficiency values above 0.5. However, all models showed poor performance in physiographic sections that experience significant snow accumulation.

Screening of chemicals migrating from plastic food contact materials for oven and microwave applications by liquid and gas chromatography - Orbitrap mass spectrometry.

Contamination of food with chemicals migrating from food contact materials (FCMs) is an important area of food safety. This study was aimed to investigate migration of chemicals from plastic FCMs used for microwave and conventional oven heating. Migration tests were conducted for samples of microwave trays, microwave oven bags, and oven bags. GC- and LC-Orbitrap mass spectrometry (MS) was used for non-targeted screening and identification of chemicals with mass error <5 ppm. A non-targeted identification approach was validated with isotopically labeled chemicals to establish acceptable criteria for identification of migrated compounds. A total of 74 migrated compounds were tentatively identified: 24 chemicals by GC-Orbitrap MS with electron ionization (EI), plus 35 and 19 by LC-Orbitrap MS electrospray ionization (ESI) with positive and negative polarities, respectively. Four migrated chemicals were identified by more than one instrumental analysis. Both intentionally added substances (IAS), i.e. additives used in the production of polymeric materials and plastics, and non-intentionally added substances (NIAS), i.e. derivatives and degradation/oxidation products of IAS, were identified among the migrated chemicals. The levels of 25 migrated chemicals were significantly different (p < 0.05) between microwave treatments and conventional oven treatments, where 20 migrants had higher levels for microwave compared with 5 for conventional oven treatments. For several identified chemicals, no previous reports on their migration from FCMs were found.

Sensitivity of Riparian Buffer Designs to Climate Change-Nutrient and Sediment Loading to Streams: A Case Study in the Albemarle-Pamlico River Basins (USA) Using HAWQS.

Riparian buffer zones (RBZs) provide multiple benefits to watershed ecosystems. We aimed to conduct an extensive sensitivity analysis of the RBZ designs to climate change nutrient and sediment loadings to streams. We designed 135 simulation scenarios starting with the six baselines RBZs (grass, urban, two-zone forest, three-zone forest, wildlife, and naturalized) in three 12-digit Hydrologic Unit Code watersheds within the Albemarle-Pamlico river basin (USA). Using the hydrologic and water quality system (HAWQS), we assessed the sensitivity of the designs to five water quality indicator (WQI) parameters: dissolved oxygen (DO), total phosphorous (TP), total nitrogen (TN), sediment (SD), and biochemical oxygen demand (BD). To understand the climate mitigation potential of RBZs, we identified a subset of future climate change projection models of air temperature and precipitation using EPA's Locating and Selecting Scenarios Online tool. Analyses revealed optimal RBZ designs for the three watersheds. In terms of watershed ecosystem services sustainability, the optimal Urban RBZ in contemporary climate (1983-2018) reduced SD from 61-96%, TN from 34-55%, TP from 9-48%, and BD from 53-99%, and raised DO from 4-10% with respect to No-RBZ in the three watersheds. The late century's (2070-2099) extreme mean annual climate changes significantly increased the projected SD and BD; however, the addition of urban RBZs was projected to offset the climate change reducing SD from 28-94% and BD from 69-93% in the watersheds. All other types of RBZs are also projected to fully mitigate the climate change impacts on WQI parameters except three-zone RBZ.

Integrating Inland and Coastal Water Quality Data for Actionable Knowledge.

Water quality measures for inland and coastal waters are available as discrete samples from professional and volunteer water quality monitoring programs and higher-frequency, near-continuous data from automated in situ sensors. Water quality parameters also are estimated from model outputs and remote sensing. The integration of these data, via data assimilation, can result in a more holistic characterization of these highly dynamic ecosystems, and consequently improve water resource management. It is becoming common to see combinations of these data applied to answer relevant scientific questions. Yet, methods for scaling water quality data across regions and beyond, to provide actionable knowledge for stakeholders, have emerged only recently, particularly with the availability of satellite data now providing global coverage at high spatial resolution. In this paper, data sources and existing data integration frameworks are reviewed to give an overview of the present status and identify the gaps in existing frameworks. We propose an integration framework to provide information to user communities through the the Group on Earth Observations (GEO) AquaWatch Initiative. This aims to develop and build the global capacity and utility of water quality data, products, and information to support equitable and inclusive access for water resource management, policy and decision making.

Spatio-Temporal Modeling for Forecasting High-Risk Freshwater Cyanobacterial Harmful Algal Blooms in Florida.

Due to the occurrence of more frequent and widespread toxic cyanobacteria events, the ability to predict freshwater cyanobacteria harmful algal blooms (cyanoHAB) is of critical importance for the management of drinking and recreational waters. Lake system specific geographic variation of cyanoHABs has been reported, but regional and state level variation is infrequently examined. A spatio-temporal modeling approach can be applied, via the computationally efficient Integrated Nested Laplace Approximation (INLA), to high-risk cyanoHAB exceedance rates to explore spatio-temporal variations across statewide geographic scales. We explore the potential for using satellite-derived data and environmental determinants to develop a short-term forecasting tool for cyanobacteria presence at varying space-time domains for the state of Florida. Weekly cyanobacteria abundance data were obtained using Sentinel-3 Ocean Land Color Imagery (OLCI), for a period of May 2016-June 2019. Time and space varying covariates include surface water temperature, ambient temperature, precipitation, and lake geomorphology. The hierarchical Bayesian spatio-temporal modeling approach in R-INLA represents a potential forecasting tool useful for water managers and associated public health applications for predicting near future high-risk cyanoHAB occurrence given the spatio-temporal characteristics of these events in the recent past. This method is robust to missing data and unbalanced sampling between waterbodies, both common issues in water quality datasets.

Quantification and valuation of ecosystem services in life cycle assessment: Application of the cascade framework to rice farming systems.

The integration of ecosystem service (ES) assessment with life cycle assessment (LCA) is important for developing decision support tools for environmental sustainability. A prequel study has proposed a 4-step methodology that integrates the ES cascade framework within the cause-effect chain of life cycle impact assessment (LCIA) to characterize the physical and monetary impacts on ES provisioning due to human interventions. We here follow the suggested steps in the abovementioned study, to demonstrate the first application of the integrated ES-LCIA methodology and the added value for LCA studies, using a case study of rice farming in the United States, China, and India. Four ES are considered, namely carbon sequestration, water provisioning, air quality regulation, and water quality regulation. The analysis found a net negative impact for rice farming systems in all three rice producing countries, meaning the detrimental impacts of rice farming on ES being greater than the induced benefits on ES. Compared to the price of rice sold in the market, the negative impacts represent around 2%, 6%, and 4% of the cost of 1 kg of rice from China, India, and the United States, respectively. From this case study, research gaps were identified in order to develop a fully operationalized ES-LCIA integration. With such a framework and guidance in place, practitioners can more comprehensively assess the impacts of life cycle activities on relevant ES provisioning, in both physical and monetary terms. This may in turn affect stakeholders' availability to receive such benefits from ecosystems in the long run.

Thoracic underreplication in Drosophila species estimates a minimum genome size and the dynamics of added DNA.

Many cells in the thorax of Drosophila were found to stall during replication, a phenomenon known as underreplication. Unlike underreplication in nuclei of salivary and follicle cells, this stall occurs with less than one complete round of replication. This stall point allows precise estimations of early-replicating euchromatin and late-replicating heterochromatin regions, providing a powerful tool to investigate the dynamics of structural change across the genome. We measure underreplication in 132 species across the Drosophila genus and leverage these data to propose a model for estimating the rate at which additional DNA is accumulated as heterochromatin and euchromatin and also predict the minimum genome size for Drosophila. According to comparative phylogenetic approaches, the rates of change of heterochromatin differ strikingly between Drosophila subgenera. Although these subgenera differ in karyotype, there were no differences by chromosome number, suggesting other structural changes may influence accumulation of heterochromatin. Measurements were taken for both sexes, allowing the visualization of genome size and heterochromatin changes for the hypothetical path of XY sex chromosome differentiation. Additionally, the model presented here estimates a minimum genome size in Sophophora remarkably close to the smallest insect genome measured to date, in a species over 200 million years diverged from Drosophila.

Investigating the Suitability of Semicarbazide as an Indicator of Preharvest Nitrofurazone Use in Raw Chicken.

ABSTRACT: Semicarbazide (SEM) is the U.S. Food and Drug Administration's official marker for nitrofurazone use in food animals. The U.S. Department of Agriculture Food Safety and Inspection Service conducted a study to evaluate the source of SEM that was identified by a U.S. trading partner in a subset of chicken samples presented for inspection, even though nitrofurazone has been banned from use in U.S. food-producing animals since 2002. The study design included analyses to detect and quantify total and bound SEM in chicken collected from the eight U.S. establishments that were associated with the reported detection of SEM. Samples were collected immediately following evisceration, chilling, and cutting carcass into parts (cut-up). Although antimicrobial interventions (processes to reduce pathogen concentrations) are typically used at all three of these processing steps, the product contact time during chilling is significantly longer (hours versus seconds) than during evisceration and cut-up. In addition, parts were analyzed after 0, 10, 20, and 30 days of frozen storage. No postevisceration samples tested positive for SEM; however, most samples collected postchilling and after cut-up tested positive. The absence of SEM in postevisceration samples and detection in the subsequent postchilling samples and after the cut-up samples suggest that the detection of SEM in the sampled products is not indicative of preharvest nitrofurazone use and may be a result of postharvest processing in these establishments.

The European Medicines Agency Review of Kymriah (Tisagenlecleucel) for the Treatment of Acute Lymphoblastic Leukemia and Diffuse Large B-Cell Lymphoma.

Chimeric antigen receptor (CAR)-engineered T-cell therapy is becoming one of the most promising approaches in the treatment of cancer. On June 28, 2018, the Committee for Advanced Therapies (CAT) and the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Kymriah for pediatric and young adult patients up to 25 years of age with B-cell acute lymphoblastic leukemia (ALL) that is refractory, in relapse after transplant, or in second or later relapse and for adult patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL) after two or more lines of systemic therapy. Kymriah became one of the first European Union-approved CAR T therapies. The active substance of Kymriah is tisagenlecleucel, an autologous, immunocellular cancer therapy that involves reprogramming the patient's own T cells to identify and eliminate CD19-expressing cells. This is achieved by addition of a transgene encoding a CAR. The benefit of Kymriah was its ability to achieve remission with a significant duration in patients with ALL and an objective response with a significant duration in patients with DLBCL. The most common hematological toxicity was cytopenia in both patients with ALL and those with DLBCL. Nonhematological side effects in patients with ALL were cytokine release syndrome (CRS), infections, secondary hypogammaglobulinemia due to B-cell aplasia, pyrexia, and decreased appetite. The most common nonhematological side effects in patients with DLBCL were CRS, infections, pyrexia, diarrhea, nausea, hypotension, and fatigue. Kymriah also received an orphan designation on April 29, 2014, following a positive recommendation by the Committee for Orphan Medicinal Products (COMP). Maintenance of the orphan designation was recommended at the time of marketing authorization as the COMP considered the product was of significant benefit for patients with both conditions. IMPLICATIONS FOR PRACTICE: Chimeric antigen receptor (CAR)-engineered T-cell therapy is becoming the most promising approach in cancer treatment, involving reprogramming the patient's own T cells with a CAR-encoding transgene to identify and eliminate cancer-specific surface antigen-expressing cells. On June 28, 2018, Kymriah became one of the first EMA approved CAR T therapies. CAR T technology seems highly promising for diseases with single genetic/protein alterations; however, for more complex diseases there will be challenges to target clonal variability within the tumor type or clonal evolution during disease progression. Products with a lesser toxicity profile or more risk-minimization tools are also anticipated.

Comparison and Evaluation of Gridded Precipitation Datasets in a Kansas Agricultural Watershed Using SWAT.

Gridded precipitation datasets are becoming a convenient substitute for gauge measurements in hydrological modeling; however, these data have not been fully evaluated across a range of conditions. We compared four gridded datasets (Daily Surface Weather and Climatological Summaries [DAYMET], North American Land Data Assimilation System [NLDAS], Global Land Data Assimilation System [GLDAS], and Parameter-elevation Regressions on Independent Slopes Model [PRISM]) as precipitation data sources and evaluated how they affected hydrologic model performance when compared with a gauged dataset, Global Historical Climatology Network-Daily (GHCN-D). Analyses were performed for the Delaware Watershed at Perry Lake in eastern Kansas. Precipitation indices for DAYMET and PRISM precipitation closely matched GHCN-D, whereas NLDAS and GLDAS showed weaker correlations. We also used these precipitation data as input to the Soil and Water Assessment Tool (SWAT) model that confirmed similar trends in streamflow simulation. For stations with complete data, GHCN-D based SWAT-simulated streamflow variability better than gridded precipitation data. During low flow periods we found PRISM performed better, whereas both DAYMET and NLDAS performed better in high flow years. Our results demonstrate that combining gridded precipitation sources with gauge-based measurements can improve hydrologic model performance, especially for extreme events.

PiSCES: Pi(scine) stream community estimation system.

The Piscine Stream Community Estimation System (PiSCES) provides users with a hypothesized fish community for any stream reach in the conterminous United States using information obtained from Nature Serve, the US Geological Survey (USGS), StreamCat, and the Peterson Field Guide to Freshwater Fishes of North America for over 1000 native and non-native freshwater fish species. PiSCES can filter HUC8-based fish assemblages based on species-specific occurrence models; create a community abundance/biomass distribution by relating relative abundance to mean body weight of each species; and allow users to query its database to see ancillary characteristics of each species (e.g., habitat preferences and maximum size). Future efforts will aim to improve the accuracy of the species distribution database and refine/augment increase the occurrence models. The PiSCES tool is accessible at the EPA's Quantitative Environmental Domain (QED) website at https://qed.epacdx.net/pisces/.

Mapping Aedes aegypti (Diptera: Culicidae) and Aedes albopictus Vector Mosquito Distribution in Brownsville, TX.

Aedes mosquitoes are vectors of several emerging diseases and are spreading worldwide. We investigated the spatiotemporal dynamics of Aedes aegypti (Linnaeus) and Aedes albopictus (Skuse) mosquito trap captures in Brownsville, TX, using high-resolution land cover, socioeconomic, and meteorological data. We modeled mosquito trap counts using a Bayesian hierarchical mixed-effects model with spatially correlated residuals. The models indicated an inverse relationship between temperature and mosquito trap counts for both species, which may be due to the hot and arid climate of southern Texas. The temporal trend in mosquito populations indicated Ae. aegypti populations peaking in the late spring and Ae. albopictus reaching a maximum in winter. Our results indicated that seasonal weather variation, vegetation height, human population, and land cover determine which of the two Aedes species will predominate.

Phylogenomics Identifies an Ancestral Burst of Gene Duplications Predating the Diversification of Aphidomorpha.

Aphids (Aphidoidea) are a diverse group of hemipteran insects that feed on plant phloem sap. A common finding in studies of aphid genomes is the presence of a large number of duplicated genes. However, when these duplications occurred remains unclear, partly due to the high relatedness of sequenced species. To better understand the origin of aphid duplications we sequenced and assembled the genome of Cinara cedri, an early branching lineage (Lachninae) of the Aphididae family. We performed a phylogenomic comparison of this genome with 20 other sequenced genomes, including the available genomes of five other aphids, along with the transcriptomes of two species belonging to Adelgidae (a closely related clade to the aphids) and Coccoidea. We found that gene duplication has been pervasive throughout the evolution of aphids, including many parallel waves of recent, species-specific duplications. Most notably, we identified a consistent set of very ancestral duplications, originating from a large-scale gene duplication predating the diversification of Aphidomorpha (comprising aphids, phylloxerids, and adelgids). Genes duplicated in this ancestral wave are enriched in functions related to traits shared by Aphidomorpha, such as association with endosymbionts, and adaptation to plant defenses and phloem-sap-based diet. The ancestral nature of this duplication wave (106-227 Ma) and the lack of sufficiently conserved synteny make it difficult to conclude whether it originated from a whole-genome duplication event or, alternatively, from a burst of large-scale segmental duplications. Genome sequencing of other aphid species belonging to different Aphidomorpha and related lineages may clarify these findings.

Complete Genome Sequence of Multidrug-Resistant Salmonella enterica Serovar I 4,[5],12:i:- 2015 U.S. Pork Outbreak Isolate USDA15WA-1.

The genome of a multidrug-resistant (MDR) Salmonella enterica subsp. enterica serovar I 4,[5],12:i:- isolate from the 2015 U.S. pork outbreak was sequenced. The complete nucleotide sequence of USDA15WA-1 is 5,031,277 bp, including Salmonella genomic island 4 encoding tolerance to multiple metals and an MDR module inserted in the fljB region.

Towards integrating the ecosystem services cascade framework within the Life Cycle Assessment (LCA) cause-effect methodology.

The assessment of ecosystem services (ES) is covered in a fragmented manner by environmental decision support tools that provide information about the potential environmental impacts of supply chains and their products, such as the well-known Life Cycle Assessment (LCA) methodology. Within the flagship project of the Life Cycle Initiative (hosted by UN Environment), aiming at global guidance for life cycle impact assessment (LCIA) indicators, a dedicated subtask force was constituted to consolidate the evaluation of ES in LCA. As one of the outcomes of this subtask force, this paper describes the progress towards consensus building in the LCA domain concerning the assessment of anthropogenic impacts on ecosystems and their associated services for human well-being. To this end, the traditional LCIA structure, which represents the cause-effect chain from stressor to impacts and damages, is re-casted and expanded using the lens of the ES 'cascade model'. This links changes in ecosystem structure and function to changes in human well-being, while LCIA links the effect of changes on ecosystems due to human impacts (e.g. land use change, eutrophication, freshwater depletion) to the increase or decrease in the quality and/or quantity of supplied ES. The proposed cascade modelling framework complements traditional LCIA with information about the externalities associated with the supply and demand of ES, for which the overall cost-benefit result might be either negative (i.e. detrimental impact on the ES provision) or positive (i.e. increase of ES provision). In so doing, the framework introduces into traditional LCIA the notion of "benefit" (in the form of ES supply flows and ecosystems' capacity to generate services) which balances the quantified environmental intervention flows and related impacts (in the form of ES demands) that are typically considered in LCA. Recommendations are eventually provided to further address current gaps in the analysis of ES within the LCA methodology.

Life cycle assessment of a rainwater harvesting system compared with an AC condensate harvesting system.

This study presents a life cycle assessment (LCA) of a rainwater harvesting (RWH) system and an air-conditioning condensate harvesting (ACH) system for non-potable water reuse. U.S. commercial buildings were reviewed to design rooftop RWH and ACH systems for one to multi-story buildings' non-potable water demand. A life cycle inventory was compiled from the U.S. EPA's database. Nine scenarios were analyzed, including baseline RWH system, ACH system, and combinations of the two systems adapted to 4-story and 19-story commercial buildings in San Francisco and a 4-story building in Washington, DC. Normalization of 11 life cycle impact assessment categories showed that RWH systems in 4-story buildings at both locations outperformed ACH systems (45-80% of ACH impacts) except equivalent in Evaporative Water Consumption. However, San Francisco's ACH system in 19-story building outperformed the RWH system (51-83% of RWH impacts) due to the larger volume of ACH collection, except equivalent in Evaporative Water Consumption. For all three buildings, the combined system preformed equivalently to the better-performing option (≤4-8% impact difference compared to the maximum system). Sensitivity analysis of the volume of water supply and building occupancy showed impact-specific results. Local climatic conditions, rainfall, humidity, water collections and demands are important when designing building-scale RWH and ACH systems. LCA models are transferrable to other locations with variable climatic conditions for decision-making when developing and implementing on-site non-potable water systems.