Faculty Publications from The Water Center

Sprinkler Irrigation: A Volatile Organic Compound Remediation Alternative

Roy F. Spalding et al. — Tue, 14 Aug 2012 10:12:15 PDT

Sprinkler irrigation has the potential not only to cheaply and effectively remove volatile organic compounds (VOCs) from contaminated ground water but also use the water beneficially and eliminate the costly disposal of both the remediated water and the contaminants. Removal of VOCs from water involves volatilization, which releases the VOCs from the liquid phase to the gaseous phase.

A conventionally designed sprinkler irrigation system was tested near Hastings, Nebraska, to assess its efficacy for removing VOCs in pumped ground water. VOCs in the ground water include 7,1,2-trichloroethylene( TCE), ethylene dibromide (EDB), 1,1,1-trichloroethane (TCA), and carbon tetrachloride (CT). Factors possibly influencing volatilization include nozzle size, system pressure, impact pad design, flow rate, and temperature.

Transformation of Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) by Permanganate

Chanat Chokejaroenrat et al. — Wed, 21 Sep 2011 12:40:50 PDT

The chemical oxidant permanganate (MnO₄⁻) has been shown to effectively transform hexa-hydro-1,3,5-trinitro-1,3,5-triazine (RDX) at both the laboratory and fieldscales. We treated RDX with MnO₄⁻ with the objective of quantifying the effects of pH and temperature on destruction kinetics and determining reaction rates. A nitrogen mass balance and the distribution of reaction products were used to provide insight into reaction mechanisms. Kinetic experiments (at pH ~7, 25 °C) verifiedthat RDX−MnO₄⁻ reaction was first-order with respect to MnO₄⁻ and initial RDX concentration (second-order rate: 4.2 × 10⁻⁵ M⁻¹ s⁻¹). Batch experiments showed that choice of quenching agents (MnSO₄, MnCO₃, and H₂O₂) influenced sample pH and product distribution. When MnCO₃ was used as a quenching agent, the pH of the RDX−MnO₄⁻ solution was relatively unchanged and N₂O and NO₃⁻ constituted 94% of the N-containing products after 80% of the RDX was transformed. On the basis of the preponderance of N₂O produced under neutral pH (molar ratio N₂O/NO₃ ~5:1), no strong pH effect on RDX−MnO₄⁻ reaction rates, a lower activation energy than the hydrolysis pathway, and previous literature on MnO₄⁻ oxidation of amines, we propose that RDX−MnO₄⁻ reaction involves direct oxidation of the methylene group (hydride abstraction), followed by hydrolysis of the resulting imides, and decarboxylation of the resulting carboxylic acids to form N₂O, CO₂, and H₂O.

Atrazine in a Stream-Aquifer System: Transport of Atrazine and Its Environmental Impact Near Ashland, Nebraska

Darryl A. Blum et al. — Fri, 09 Apr 2010 10:36:34 PDT

The municipal wellfield for Lincoln, Nebraska, consists of 44 wells located adjacent to the Platte River near Ashland, Nebraska. The herbicide atrazine was monitored in the river and two transects of monitoring wells. The amount of atrazine transported down the Platte River in 1989, 1990, and 1991 was shown to increase each year. Induced recharge from the Platte River results in movement of atrazine from the river into the aquifer. A 21-day lag time was determined for the movement of atrazine from the river to a transect of monitoring wells 10 feet west of the bank. The role that colloids play on the transport of atrazine was determined to be insignificant. A small percentage of atrazine found in the river was determined to come from rain water. The infiltration of agrichemical-contaminated river water was shown to significantly reduce the quality of raw water and finished water being produced by the adjacent aquifer.

Anaerobic Biodegradation of RDX and TCE: Single- and Dual-Contaminant Batch Tests

Travis S. M. Young et al. — Fri, 22 Jan 2010 14:34:09 PST

Several sites in the United States have groundwater contaminated with mixtures of high explosives and chlorinated solvents. This research examined the ability of two microbial cultures (anaerobic sludge and a facultative enrichment culture) to biodegrade single- and dual-contaminant mixtures of trichloroethene (TCE) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) under anaerobic conditions. In single component batch tests, both cultures degraded 0.6–1 mg RDX/L and its nitroso metabolites to below detection limits in <7 days. During initial 9-day TCE biodegradation tests, the anaerobic sludge did not transform TCE, whereas the facultative culture transformed approximately 10% of the initial 1.4 mg TCE/L. Prior to dual-contaminant batch tests, both cultures were grown in the presence of TCE. Subsequently, both acclimated cultures rapidly biodegraded mixtures of RDX and TCE. Both cultures degraded RDX and RDX-nitroso compounds to below detection limits in <4 days. In the same tests, TCE-acclimated anaerobic sludge converted TCE primarily to cis-dichloroethene (cis-DCE), while the acclimated facultative culture produced cis-DCE and other chlorinated metabolites. These preliminary results demonstrate that anaerobic bioremediation may be part of a feasible groundwater remediation alternative for mixtures of TCE and RDX.

Occurrence and biological effect of exogenous steroids in the Elkhorn River, Nebraska, USA

Alan S. Kolok et al. — Fri, 22 Jan 2010 13:39:25 PST

Recent studies of surface waters in North America, Japan, and Europe have reported the presence of steroidogenic agents as contaminants. The current study has three objectives: 1) to determine if steroidogenic compounds are present in the Elkhorn River, 2) to determine if sediments collected from the Elkhorn River can act as a source of steroidogenic compounds to aquatic organisms, and 3) to determine if site-specific biological effects are apparent in the hepatic gene expression of fathead minnows. Evidence was obtained using three approaches: 1) deployment of polar organic chemical integrative samplers (POCIS), 2) deployment of caged fathead minnows, and 3) a laboratory experiment in which POCIS and fish were exposed to sediments from the deployment sites. Deployment sites included: the Elkhorn River immediately downstream from a Nebraska wastewater treatment plant, two waterways (Fisher Creek and Sand Creek) likely to be impacted by runoff from cattle feeding operations, and a reference site unlikely to be impacted by waste water inputs. The POCIS extracts were analyzed for a number of natural steroids and metabolites, as well as four different synthetic steroids: ethinylestradiol, zearalonol, 17β-trenbolone and melengestrol acetate. Estrogenic and androgenic metabolites, as well as progesterone and trace levels of melengestrol acetate were detected in POCIS deployed at each site. POCIS deployed in tanks containing field sediments from the four sites did not accumulate the synthetic steroids except for ethinylestradiol, which was detected in the aquarium containing sediments collected near the wastewater treatment plant. Fish deployed in Sand Creek and at the wastewater treatment plant experienced significantly elevated levels of gene expression for two genes (StAR and P450scc) relative to those deployed in Fisher Creek. Fish exposed to the sediments collected from Sand Creek had significantly higher levels of hepatic StAR and P450scc gene expression than did fish exposed to sediments from the two other field sites, as well as the no-sediment control tank. In conclusion: 1) detectable levels of steroidogenic compounds were detected in passive samplers deployed in the Elkhorn River, 2) sediments do not appear to be a significant source for steroidogenic compounds, and 3) site-specific differences were found in mRNA expression among the different treatment groups of fish; however, a functional explanation for these differences is not readily forthcoming.

Occurrence of sulfonamide antimicrobials in private water wells in Washington County, Idaho, USA

Angela L. Batt et al. — Fri, 08 Jan 2010 12:38:28 PST

County (Weiser, Idaho) were collected to assess the impact of a nearby confined animal feeding operation (CAFO) on the quality of the local groundwater. All six samples were found contaminated by two veterinary antimicrobials, sulfamethazine (at concentrations from 0.076 to 0.22 μg/l) and sulfadimethoxine (at concentrations from 0.046 to 0.068 μg/l). These groundwater samples also contained elevated concentrations of nitrate and ammonium. Three of the sampled wells have nitrate levels that exceeded the maximum contaminant level set by the US Environmental Protection Agency for drinking water, with nitrate concentration as high as 39.1 mg/l. All but one well showed nitrate, which instead contained ammonium at 1.22 mg/l. Analysis of the nitrate and ammonium in these samples by isotopic ratio mass spectrometry indicated δ¹⁵N characteristic of an animal or human waste source. Results from this study underscore the role of CAFO as an important source of antibiotic contamination of groundwater.

Estrogenic Compounds Downstream from Three Small Cities in Eastern Nebraska: Occurrence and Biological Effect

Marlo K. Sellin et al. — Fri, 08 Jan 2010 11:37:44 PST

Recent studies have detected estrogenic compounds in surface waters in North America and Europe. Furthermore, the presence of estrogenic compounds in surface waters has been attributed, in some cases, to the discharge of wastewater treatment plant (WWTP) effluent. The primary objective of the current study was to determine if WWTP effluent contributes estrogens to the surface waters of Nebraska. A second objective of this study was to determine if estrogens were found in concentrations sufficient enough to manifest feminizing effects on fish. These objectives were satisfied by deploying polar organic chemical integrative samplers (POCIS) and caged fathead minnows at eight field sites. Deployment sites included: three reference sites (Pawnee Creek, the Little Blue River, and the Middle Loup River), two sites upstream of the WWTPs at Grand Island and Columbus, and three sites downstream of the WWTPs at Grand Island, Columbus, and Hastings. Following the seven day deployments, POCIS extracts were analyzed for estrone, 17β-estradiol, estriol and 17α-ethinylestradiol using liquid chromatography tandem mass spectrometry (LC/MS/MS). 17β-estradiol was detected in POCIS from six of the eight field sites with the greatest quantities recovered in POCIS deployed downstream from the Grand Island and Hastings WWTPs. Estrone was detected only in the POCIS deployed downstream from the Grand Island and Hastings WWTPs. Estrogenic effects were detected in caged minnows analyzed for the hepatic mRNA expression of two estrogen- responsive genes, vitellogenin (vg1) and estrogen receptor α (ERα). Fish deployed at the site where the greatest quantities of estrogens were recovered (Hastings) had significantly higher expression of both vg1 and ERα than fish deployed at any of the other sites. These results confirm that WWTP effluent contributes biologically significant levels of estrogens to Nebraska surface waters.

Remediating RDX-Contaminated Ground Water with Permanganate: Laboratory Investigations for the Pantex Perched Aquifer

M. L. Adam et al. — Fri, 11 Dec 2009 13:57:14 PST

Ground water beneath the U.S. Department of Energy Pantex Plant is contaminated with the high explosive RDX (hexahydro-1,3,5- trinitro-1,3,5 triazine). The USDOE Innovative Treatment and Remediation Demonstration (ITRD) program identified in situ oxidation by permanganate as a technology fit for further investigation. We evaluated the efficacy of KMnO₄ to transform and mineralize RDX by determining degradation kinetics and carbon mass balances using ¹⁴C-RDX. Aqueous RDX solutions (2–5 mg L^–1) and RDX-contaminated slurries (50% solids, w/v) were treated with KMnO₄ at 1000, 2000, 4000, and 20,000 mg L^–1. Treating an aqueous RDX solution of 2.8 mg L^–1 with 20,000 mg KMnO₄ L^–1 decreased RDX to 0.1 mg L^–1 within 11 d while cumulative mineralization proceeded for 14 d until 87% of the labeled carbon was trapped as ¹⁴CO₂. Similar cumulative mineralization was obtained when Pantex aquifer material was included in the solution matrix. Other experiments using 4000 mg KMnO₄ L^–1 showed that initial RDX concentrations (1.3–10.4 mg L^–1) or initial pH (4–11) had little effect on reaction rates. Attempts to identify RDX degradates and reaction products showed that N₂O was a product of permanganate oxidation and constituted 20 to 30% of the N balance. Time-course measurements of a ¹⁴C-RDX solution treated with KMnO₄ revealed few ¹⁴C-labeled degradates but through liquid chromatography–mass spectrometry (LC–MS) analysis, we present evidence that 4-nitro-2,4-diazabutanol is formed. Aquifer microcosm studies confirmed that the transformation products not mineralized by KMnO₄ were much more biodegradable than parent RDX. These results indicate permanganate can effectively transform and mineralize RDX in the presence of aquifer material and support its use as an in situ chemical oxidation treatment for the Pantex perched aquifer.

Field-Scale Cleanup of Atrazine and Cyanazine Contaminated Soil with a Combined Chemical-Biological Approach

Manmeet Waria et al. — Fri, 11 Dec 2009 13:42:51 PST

A former agrichemical dealership in western Nebraska was suspected of having contaminated soil. Our objective was to characterize and remediate the contaminated site by a combined chemical-biological approach. This was accomplished by creating contour maps of the on-site contamination, placing the top 60 cm of contaminated soil in windrows and mixing with a mechanical high-speed mixer. Homogenized soil containing both atrazine [6-chloro-N-ethyl-N´-isopropyl-1,3,5-triazine- 2,4-diamine] and cyanazine {2-[[4-chloro-6-(ethylamino)-1,3,5- triazin-2-yl] amino]-2-methylpropanenitrile} was then used in laboratory investigations to determine optimum treatments for pesticide destruction. Iron suspension experiments verified that zerovalent iron (Fe⁰) plus ferrous sulfate (FeSO₄•7H₂O) removed more than 90% of both atrazine and cyanazine within 14 days. Liquid chromatography/mass spectrometry (LC/ MS) analysis of the atrazine solution after treating with Fe⁰ and ferrous sulfate identified several degradation products commonly associated with biodegradation (i.e., deethlyatrazine (DEA), deisopropylatrazine (DIA), hydroxyatrazine (HA), and ammelines). Biological treatment evaluated emulsified soybean [Glycine max (L.) Merr.] oil (EOS) as a carbon source to stimulate biodegradation in static soil microcosms. Combining emulsified soybean oil with the chemical amendments resulted in higher destruction efficiencies (80–85%) and reduced the percentage of FeSO₄ needed. This chemical-biological treatment (Fe⁰ + FeSO₄ + EOS, EOS Remediation, Raleigh, NC) was then applied with water to 275 m³ of contaminated soil in the field. Windrows were tightly covered with clear plastic to increase soil temperature and maintain soil water content. Temporal sampling (0–342 d) revealed atrazine and cyanazine concentrations decreased by 79 to 91%. These results provide evidence that a combined chemical-biological approach can be used for on-site, field-scale treatment of pesticide-contaminated soil.

Emerging Chemicals and Analytical Methods (2005)

Matthew C. Morley et al. — Fri, 11 Dec 2009 13:17:38 PST

Emerging contaminants in the water environment continues to be a strong research focus, as evidenced by the abundance of material published during 2004. This review summarizes peer-reviewed literature pertinent to the field of environmental engineering and science and related to analysis, occurrence, and fate of emerging chemical contaminants in the water environment, focusing on the following broad categories of emerging organic contaminants: antibiotics and pharmaceuticals; personal care products ingredients (PCPIs), endocrine disrupting compounds (EDCs), halogenated compounds (particularly brominated and fluorinated compounds), and disinfection byproducts (DBPs). To maintain this focus, articles pertaining specifically to human and ecological toxicity, bioconcentration or bioaccumulation, risk assessments, and innovative treatment and destruction methods are not included in this review. Additionally, summaries of literature covering organometallic compounds are not included in this review as in past years. Because of the sheer volume of literature covered by this topic, this review should not be considered to be comprehensive.

Emerging Chemicals and Analytical Methods (2006)

Matthew C. Morley et al. — Fri, 11 Dec 2009 13:13:02 PST

This review summarizes peer-reviewed literature related to analysis, occurrence, and fate of emerging chemical contaminants in the water environment. The review focuses on the following broad categories of emerging contaminants: pharmaceuticals and personal care products (PPCPs); endocrine disrupting compounds (EDCs), including hormones, surfactants, and plasticizers; and brominated flame retardants (BFRs). Although many of the cited articles refer to multiple types of contaminants (particularly hormones and pharmaceuticals), each article is summarized in only one section. Articles pertaining to specific treatment methods, risk assessments, or biological effects are not included in this review, and articles covering disinfection byproducts (DBPs), fluorinated compounds, and organometallics are not reviewed as in past years. Because of the ever-increasing volume and scope of literature pertaining to emerging contaminants, this review should not be considered to be comprehensive; however, a broad range of literature that is relevant to environmental engineers and scientists is summarized.

Detection, Occurrence and Fate of Emerging Contaminants in Agricultural Environments (2008)

Daniel D. Snow et al. — Fri, 11 Dec 2009 13:08:21 PST

Agricultural settings are affected by a unique set of environmental contaminants typically associated with land use. Nutrients and sediments from run-off and erosion have historically been, and continue to be, studied and understood with respect to their impacts to aquatic environments. Studies involving newer classes of contaminants, such as pharmaceuticals and steroids, are becoming more prevalent as methods for measuring these compounds become available. These “emerging” contaminants clearly have potential to enter the environment and cause known or suspected adverse ecological or human health effects. Release of these contaminants to the environment has occurred for quite some time, but methods for their detection at environmentally-relevant concentrations have only recently become available.

Studies involving emerging contaminants typically focus on the environmental fate and effects of surfactants, antibiotics and other pharmaceuticals, steroid hormones and other endocrine-disrupting compounds (EDCs), fire retardants, sunscreens, disinfection byproducts, new pesticides and pesticide metabolites, and naturally-occurring algal toxins. Detection of these and wastewater-related contaminants in environmental matrices (water, wastewater, soils and sediments) is particularly challenging because of the low detection limits required, the complex nature of the samples, and difficulty in separating these compounds from interferences. New extraction and clean-up techniques, coupled with improvements in instrumental technologies provide the needed sensitivity and specificity for accurate measurement.

The objective of this paper is to review the literature published in 2007 evaluating the detection, fate, and occurrence of emerging contaminants, with a particular focus on emerging contaminants in agricultural systems. Relevant contaminants are EDCs (particularly hormones and anabolic steroids), antibiotics and other pharmaceuticals associated with wastewater, antibiotic resistance genes in bacteria and prions. Studies on pesticides and flame retardants are not reviewed unless they were evaluated in the same study.

Herbicides in Ground Water beneath Nebraska’s Management Systems Evaluation Area

Roy F. Spalding et al. — Fri, 11 Dec 2009 12:51:37 PST

Profiles of ground water pesticide concentrations beneath the Nebraska Management Systems Evaluation Area (MSEA) describe the effect of 20 years of pesticide usage on ground water in the central Platte Valley of Nebraska. During the 6-yr (1991–1996) study, 14 pesticides and their transformation products were detected in 7848 ground water samples from the unconfined water table aquifer. Triazine and acetamide herbicides applied on the site and their transformation products had the highest frequencies of detection. Atrazine [6-chloro-N-ethyl-N’-(1-methylethyl)-1,3,5-triazine-2,4,-diamine] concentrations decreased with depth and ground water age determined with ³H/³He dating techniques. Assuming equivalent atrazine input during the past 20 yr, the measured average changes in concentration with depth (age) suggest an estimated half-life of >10 yr. Hydrolysis of atrazine and deethylatrazine (DEA; 2-chloro-4-amino-6-isopropylamino-s-triazine) to hydroxyatrazine [6-hydroxy-N-ethyl-N’-(1-methylethyl)-1,3, 5-triazine-2,4-diamine] appeared to be the major degradation route. Aqueous hydroxyatrazine concentrations are governed by sorption on the saturated sediments. Atrazine was detected in the confined Ogallala aquifer in ultra-trace concentrations (0.003μgL^–1); however, the possibility of introduction during reverse circulation drilling of these deep wells cannot be eliminated. In fall 1997 sampling, metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-meth- ylethyl) acetamide] was detected in 57% of the 230 samples. Metolachlor oxanilic acid [(2-ethyl-6-methylphenyl)(2-methoxy-1-methylethyl) amino]oxo-acetic acid] was detected in most samples. In ground water profiles, concentrations of metolachlor ethane sulfonic acid [2-[(ethyl- 6-methylphenyl)(2-methoxy-1-methylethyl)amino]-2-oxo-ethanesul- fonic acid] exceeded those of deethylatrazine. Alachlor [2-chloro- N-(2,6-diethylphenyl)-N-(methoxymethyl)acetamide] was detected in <1% of the samples; however, alachlor ethane sulfonic acid [2-[(2,6- diethylphenyl)(methoxymethyl)amino]-2-oxoethanesulfonic acid] was present in most samples (63%) and was an indicator of past alachlor use.

Herbicide Loading to Shallow Ground Water beneath Nebraska’s Management Systems Evaluation Area

Roy F. Spalding et al. — Fri, 11 Dec 2009 12:28:35 PST

Better management practices can counter deterioration of ground water quality. From 1991 through 1996 the influence of improved irrigation practices on ground water pesticide contamination was assessed at the Nebraska Management SystemsEvaluation Area. Three 13.4-ha corn (Zea mays L.) fields were studied: a conventional furrow-irrigated field, a surge-irrigated field and a center pivot–irrigated field, and a center pivot–irrigated alfalfa (Medicago sativa L.) field. The corn fields received one identical banded application of Bicep (atrazine [6-chloro-N-ethyl-N’-(1-methylethyl)-1,3,5-triazine-2,4,-diamine] _ metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl) acetamide]) annually; the alfalfa field was untreated. Ground water samples were collected three times annually from 16 depths of 31 multi-level samplers. Six years of sample data indicated that a greater than 50% reduction in irrigation water on the corn management fields lowered average atrazine concentrations in the upper 1.5 m of the aquifer downgradient of the corn fields from approximately 5.5 to <0.5 μg L^–1. Increases in deethylatrazine (DEA; 2-chloro-4-amino-6-isopropyl- amino-s-triazine) to atrazine molar ratios indicated that reducing water applications enhanced microbial degradation of atrazine in soil zones. The occurrence of peak herbicide loading in ground water was unpredictable but usually was associated with heavy precipitation within days of herbicide application. Focused recharge of storm runoff that ponded in the surge-irrigated field drainage ditch, in the upgradient road ditch, and at the downgradient end of the conventionally irrigated field was a major mechanism for vertical transport. Sprinkler irrigation technology limited areas for focused recharge and promoted significantly more soil microbial degradation of atrazine than furrow irrigation techniques and, thereby, improved ground water quality.

Detection, Occurrence, and Fate of Emerging Contaminants in Agricultural Environments (2009)

Daniel D. Snow et al. — Fri, 11 Dec 2009 12:13:59 PST

Frequently studied environmental contaminants in agricultural systems include nutrients, sediments, and pesticides. These groups of contaminants typically occur at easily measured concentrations in surface run-off in agricultural watersheds. Nutrients, especially nitrogen, and pesticides have also been shown to impact ground water quality in areas susceptible to contamination. Less well-known are environmental impacts of newer classes of contaminants such as pharmaceuticals, steroids, antibiotic-resistance genes and prion proteins. These “emerging” contaminants clearly have potential to enter the environment and cause known or suspected adverse ecological or human health effects. Release of these contaminants to the environment often has occurred for quite some time, but methods for their detection at environmentally-relevant concentrations have only recently become available.

Evaluating the environmental fate and effects of emerging contaminants includes research on compounds such as surfactants, antibiotics and other pharmaceuticals, steroid hormones and other endocrine-disrupting compounds (EDCs), fire retardants, sunscreens, disinfection byproducts, new pesticides and pesticide metabolites, and naturally-occurring algal toxins. Detection of these contaminants in environmental matrices (water, wastewater, soils and sediments) is particularly challenging because of the low detection limits required, the complex nature of the samples, and difficulty in separating these compounds from interferences. New extraction and cleanup techniques, coupled with improvements in instrumental technologies provide the needed sensitivity and specificity for accurate measurement.

The objective of this paper is to review the literature published in 2008 evaluating the detection, fate, and occurrence of emerging contaminants, with a particular focus on emerging contaminants in agricultural systems. Relevant contaminants are EDCs (particularly hormones and anabolic steroids), antibiotics and other pharmaceuticals associated with wastewater, antibiotic resistance genes in bacteria and prions. Studies on pesticides and flame retardants are not reviewed unless they were evaluated in the same study.

The occurrence of illicit and therapeutic pharmaceuticals in wastewater effluent and surface waters in Nebraska

Shannon L. Bartelt-Hunt et al. — Thu, 12 Nov 2009 13:51:39 PST

Passive samplers were used to develop semi-quantitative estimates of pharmaceutical concentrations in receiving waters influenced by wastewater effluent. The occurrence and estimated concentration of twenty illicit and therapeutic pharmaceuticals and metabolites in surface waters influenced by wastewater treatment plant (WWTP) discharge and in wastewater effluents in Nebraska were determined using Polar Organic Chemical Integrative Samplers (POCIS). Samplers were installed in rivers upstream and downstream of treated WWTP discharge at four sites and in a discharge canal at a fifth location. Based on differences in estimated concentrations determined from pharmaceuticals recovered from POCIS, WWTP effluent was found to be a significant source of pharmaceutical loading to the receiving waters. Effluents from WWTPs with trickling filters or trickling filters in parallel with activated sludge resulted in the highest observed in-stream pharmaceutical concentrations. Azithromycin, caffeine, 1,7-dimethylzanthine, carbamazepine, cotinine, DEET, diphenhydramine, and sulfamethazine were detected at all locations. Methamphetamine, an illicit pharmaceutical, was detected at all but one of the sampling locations, representing only the second report of methamphetamine detected in WWTP effluent and in streams impacted by WWTP effluent.

Nebraska Water (map/poster)

Wed, 18 Feb 2009 11:29:07 PST

A 36" x 24" poster including topographical and watershed map of the state of Nebraska and inset maps showing:
Density of Active Registered Irrigation Wells - January 2008
Groundwater-Level Changes - Predevelopment to Spring 2007
Generalized Nitrate Levels in Wells Sampled, 1974 - 2006
Mean Annual Precipitation, 1971 - 2000 and Generalized Gaining/Losing Streams
DNR Designated Hydrologically-Connected Fully and Overappropriated Basins, Subbasins and Reaches, July 2008
River Basins with Coldwater and Warmwater Stream Designations
Generalized Atrazine Levels in Wells Sampled, 1974 - 2006
Threatened and Endangered Waterbirds and Fish
High Plains Aquifer, Saturated Thickness, 1997
Estimated Water Use in Nebraska in 2005

Instream Flow Legislation

Sandi Zellmer — Mon, 10 Mar 2008 22:40:41 PDT

In the west, state law historically considered water left in the stream to be wasted. Western states, which rely heavily on diversions to meet their water needs, have encouraged full appropriation of rivers and streams. In many cases, however, diversions have resulted in the depletion of stream flow reliant ecosystems and adversely affected fish, wildlife, recreation and river navigation.

A comparison of Nebraska law to the water law of other western states demonstrates that Nebraska’s existing instream flow legislation is quite narrow. Nebraska statutes impose a variety of restrictions on instream flow appropriations, many of which are unique and even unprecedented. Rather than restricting instream flow appropriations even further, it may be wise to expand instream flow protections to keep pace with contemporary norms by protecting and enhancing the value of ecosystem services such as pollution filtration, wildlife habitat and recreational activities.

The Public Interest Test for Water Appropriations

Sandi Zellmer — Mon, 10 Mar 2008 22:36:34 PDT

Nebraska, like most states, imposes a “public interest” review on applications for water appropriations, changes and transfers. However, Nebraska statutes do not provide any specific public interest criteria for use in evaluating applications for new water appropriations or intra-basin transfers. Under Neb. Rev. Stat. § 46-234, an application for a water appropriation may be refused when denial is demanded by the public interest. The director of the Department of Natural Resources (DNR) has the duty of determining whether the public interest demands the denial of a water appropriation, but is given no express statutory criteria to provide assistance in making that decision.

A Long-term Perspective on Drought in the Great Plains and West

Sherilyn C. Fritz — Mon, 10 Mar 2008 22:28:22 PDT

Management of water resources requires an understanding of the full range of natural variability and its consequences. The weather record, which spans the last 100 years or so, provides a snapshot of the contemporary history of drought and its impacts, but this record is relatively short and is inadequate for understanding long-term trends or for evaluating the magnitude of human impacts. A variety of so-called paleoclimatic records - such as tree rings, lake sediments, and sand dunes - record the history of the environment and can be used to extend the record of climatic variation to older intervals of time. These historical archives can provide a perspective on whether or not the patterns of the 20th century are representative of long-term conditions and can be used to enhance management decisions that require long-range estimates of water availability