Broad-host-range plasmids in treated wastewater effluent and receiving streams

The occurrence of broad-host-range (BHR) plasmid amplicons belonging to incompatibility (Inc) groups IncA/C, IncN, IncP, and IncW in two wastewater treatment plant (WWTP) effluents and effluent-receiving streams in Northwest Arkansas, Mud Creek and Spring Creek, was determined. Community DNA captured on filter membranes and plasmid DNA extracted from antibiotic-resistant Escherichia coli isolated from Mud Creek was used for polymerase chain reaction at amplification of partial gene sequences specific to BHR plasmids. IncP plasmid amplicons were detected in effluent and downstream sites in both streams, while IncN and IncW plasmid amplicons were detected in Spring Creek in effluent and downstream but not upstream. IncA/C plasmid amplicons, in contrast, were detected at all sites, including upstream in most samples in Spring Creek and in one sample from Mud Creek. One IncP and two IncN were the only BHR plasmid amplicons found in 85 screened antibiotic-resistant E. coli isolates, and were detected only in isolates from effluent and downstream samples. Broad-host-range plasmids frequently carry antibiotic-resistance genes and can facilitate horizontal transfer of those genes. While BHR plasmids have been detected in WWTPs, WWTPs do not target these genetic elements for destruction. This study indicates that BHR plasmids are in WWTP effluent and are introducing BHR plasmids into streams. Additionally, species other than E. coli may be better targets as indicator bacteria for future studies of the impact of treated effluent on environmental dissemination of BHR plasmids.     

A TREE‐RING RECONSTRUCTION OF STREAMFLOW FOR THE COLORADO FRONT RANGE1

ABSTRACT: Water resource planning is based primarily on 20th century instrumental records of climate and streamflow. These records are limited in length to approximately 100 years, in the best cases, and can reflect only a portion of the range of natural variability. The instrumental record neither can be used to gage the unusualness of 20th Century extreme low flow events, nor does it allow the detection of low‐frequency variability that may underlie short‐term variations in flow. In this study, tree rings are used to reconstruct mean annual streamflow for Middle Boulder Creek in the Colorado Front Range, a semi‐arid region of rapid growth and development. The reconstruction is based on a stepwise regression equation that accounts for 70 percent of the variance in the instrumental record, and extends from 1703–1987. The reconstruction suggests that the instrumental record of streamflow for Middle Boulder Creek is not representative of flow in past centuries and that several low flow events in the 19th century were more persistent than any in the 20th century. The 1840s to early 1850s period of low flow is a particularly notable event and may have coincided with a period of low flow in the Upper Colorado River Basin.     

GROUNDWATER QUALITY IN THE CORTARO AREA NORTHWEST OF TUCSON,ARIZONA1

ABSTRACT The Cortaro Area is currently the depository for much of the liquid waste from the City of Tucson. In the past, more than one-half of the sewage effluent was used for crop irrigation. However, since 1970 virtually all of the sewage effluent has been percolated in the normally dry Santa Cruz River channel. Nitrate and chloride contents were monitored monthly in water samples from about 20 large-capacity irrigation wells. Contents and seasonal trends for these constituents were closely related to the disposal of sewage effluent. Water quality problems other than nitrate include total dissolved solids, boron, coliform, and lead. High lead contents in the area appear to be a natural phenomenon and the coliform contents are likely related to poor well construction. The other quality problems are primarily due to sewage effluent.     

Pharmaceuticals and other organic chemicals in selected north-central and northwestern Arkansas streams

Recently, our attention has focused on the low level detection of many antibiotics, pharmaceuticals, and other organic chemicals in water resources. The limited studies available suggest that urban or rural streams receiving wastewater effluent are more susceptible to contamination. The purpose of this study was to evaluate the occurrence of antibiotics, pharmaceuticals, and other organic chemicals at 18 sites on seven selected streams in Arkansas, USA, during March, April, and August 2004. Water samples were collected upstream and downstream from the influence of effluent discharges in northwestern Arkansas and at one site on a relatively undeveloped stream in north-central Arkansas. At least one antibiotic, pharmaceutical, or other organic chemical was detected at all sites, except at Spavinaw Creek near Mayesville, Arkansas. The greatest number of detections was observed at Mud Creek downstream from an effluent discharge, including 31 pharmaceuticals and other organic chemicals. The detection of these chemicals occurred in higher frequency at sites downstream from effluent discharges compared to those sites upstream from effluent discharges; total chemical concentration was also greater downstream. Wastewater effluent discharge increased the concentrations of detergent metabolites, fire retardants, fragrances and flavors, and steroids in these streams. Antibiotics and associated degradation products were only found at two streams downstream from effluent discharges. Overall, 42 of the 108 chemicals targeted in this study were found in water samples from at least one site, and the most frequently detected organic chemicals included caffeine, phenol, para-cresol, and acetyl hexamethyl tetrahydro naphthalene (AHTN).     

TECHNICAL AND INSTITUTIONAL ASPECTS OF SEWAGE EFFLUENT-IRRIGATION WATER EXCHANGE,TUCSON REGION1

ABSTRACT .Many growing municipalities near irrigated agriculture are advocating a transfer of water now utilized for irrigation to municipal use. Alternatives are presented whereby this water can be transferred to municipal use in exchange for treated sewage effluent. The irrigation water would in effect be cycled through the municipal system prior to use on the farms. A case study of the Tucson region illustrates the relevant legal, economic and technical aspects. Effluent could be delivered to irrigators in Avra Valley at a cost less than that now paid for water pumped from declining water tables. In return the City of Tucson could import ground water now being used for irrigation through an existing pipeline which presently cannot be used because of a court injunction obtained by the irrigators. It appears that such an exchange agreement could be made without modification of existing statutory law. Similar exchange arrangements may prove to be feasible in other regions containing irrigated agriculture. Increased efficiency of water use can be achieved avoiding external effects which commonly arise in a direct transfer and are difficult to evaluate. High quality water is allocated to municipal use whereas nutrient-rich sewage effluent is transferred to irrigation.     

Targeted Application of Seasonal Load Duration Curves Using Multivariate Analysis in Two Watersheds Flowing Into Lake Houston1

Teague, Aarin, Philip B. Bedient, and Birnur Guven, 2011. Targeted Application of Seasonal Load Duration Curves Using Multivariate Analysis in Two Watersheds Flowing Into Lake Houston. Journal of the American Water Resources Association (JAWRA) 47(3):620‐634. DOI: 10.1111/j.1752‐1688.2011.00529.x Abstract: Water quality is a problem in Lake Houston, the primary source of drinking water for the City of Houston, Texas, due to pollutant loads coming from the influent watersheds, including Spring Creek and Cypress Creek. Statistical analysis of the historic water quality data was developed to understand the source characterization and seasonality of the watershed. Multivariate analysis including principal component, cluster, and discriminant analysis provided a custom seasonal assessment of the watersheds so that loading curves may be targeted for season specific pollutant source characterization. The load duration curves have been analyzed using data collected by the U.S. Geologic Survey with corresponding City of Houston water quality data at the sites to characterize the behavior of the pollutant sources and watersheds. Custom seasons were determined for Spring Creek and Cypress Creek watersheds and pollutant source characterization compared between the seasons and watersheds.     

CHANGING WATER BALANCE OVER TIME IN RUSH CREEK,EASTERN CALIFORNIA, 1860–19921

ABSTRACT: Rush Creek, the principal tributary to Mono Lake, has undergone profound hydrologic modifications as a result of flow regulation for hydroelectric generation and irrigation, diversions for irrigated agriculture, and diversions for water export to the City of Los Angeles. Lower Rush Creek (the lowermost 13 km downstream of Grant Lake Reservoir) was dry by 1970, but now receives flow as a result of court-ordered efforts to restore former ecological conditions. Using available historic data and recent field measurements, we constructed the water balance for Lower Rush Creek, identifying six distinct historical periods characterized by very different patterns of gain and loss. The hydrologic patterns must be understood as a basis for modeling ecosystem response to stream-flow alteration. A gradually gaining stream under natural conditions, the advent of irrigation diversions caused the middle reaches of Lower Rush Creek to be often completely dry, while irrigation-recharged springs still maintained a baseflow in the downstream “Meadows” ranch. Increased water exports from the basin subsequently reduced irrigation and dried up the springs.     

ASSESSMENT OF RESTORED RWERINE HABITAT USING RCHARC1

ABSTRACT: The Riverine Community Habitat Assessment and Restoration Concept (RCHARC) was developed to integrate habitat enhancement into the stream restoration process. RCHARC assumes that aquatic habitat quality is closely related to hydraulic diversity based upon a “comparison standard” reach approach to stream restoration. A Beta test was performed by applying the RCHARC process to Rapid Creek in Rapid City, South Dakota. Standard and restored stream reaches were selected and data were collected. A comparison of field data and velocity-depth distributions indicated that the restored stream closely replicated the standard reach. The RCHARC methodology has the potential to assess habitat quality for planned comparison reaches and indicate the level of success resulting from restoration.     

FISH RESPONSES TO TEMPERATURE TO ASSESS EFFECTS OF THERMAL DISCHARGE ON BIOLOGICAL INTEGRITY1

ABSTRACT: The applicability of the U.S Environmental Protection Agency's (USEPA) water temperature criteria in evaluating the impact of a thermal discharge from the P. H. Glatfelter Paper Company, Spring Grove, Pennsylvania, is analyzed. A review of the literature relative to 11 temperature Criteria was conducted for six fish species designated by the USEPA as “representative important species” (RIS) of the West Branch Codorus Creek, Susquehanna River drainage. The species were: Notemigonus crysolcucas (golden shiner), Notropis analostanus (satinfin shiner), Rhinichthys atratulus (blacknose dace), Catostomus comme-soni (white sucker), Lepomis gibbosus (pumpkinseed). and Micropterous salmoides (largemouth bass). It was found that by applying only USEPA suggested criteria that a complete evaluation was not satisfactory. Temperature behavior data, specifically preference and avoidance information, coupled with field sampliug was needed to properly assess the effects of the thermal effluent. The final analysis indicated that the thermal discharge of the paper company should have minimal effect on the fish community of Codorus Creek.     

STREAM PHOSPHORUS EXPORTS FROM WATERSHEDS WITH CONTRASTING LAND USES IN SOUTHERN ONTARIO1

: The export of dissolved molybdate reactive phosphorus (DMRP) from 22 watersheds in the Duffin Creek drainage basin near Toronto Ontario was measured over a 25-month period. The annual average loss varied from 0.027 to 2.11 kg P/ha. Phosphorus levels in a number of watersheds were strongly influenced by effluent from a sewage treatment plant which contributed about 68 percent of the annual DMRP input to Duffin Creek. An analysis of 12 watersheds which did not contain major point pollution sources revealed that DMRP concentration and losses had a significant positive correlation with crop area and a strong negative association with forest, abandoned farm land, and area of sand + sandy loam soils. The causal relationships underlying these simple correlations are difficult to evaluate because of considerable multicollinearity between land use, soil, and topographic variables. Analysis of a mass balance for the downstream reaches of Duffin Creek indicated that there was considerable retention of phosphorus in the river channel particularly during summer low flows.     

CITY OF TUCSON WASTE WATER EFFLUENT DELIVERY FACILITY1

ABSTRACT: The Tucson area is totally dependent on ground water, which is in increasingly short supply due to excessive overdrafts. Tucson area waste water treatment plants discharge material quantities of secondary effluent downstream, which is lost to evapotranspiration and recharge of the ground water basin. The city and the four large mining companies who share the common Santa Cruz basin ground water, recognized the common water supply problem and agreed to fund a feasibility study for mining process use of the effluent to partly alleviate the overdraft of ground water. The study analyzed the projected waste water effluent resources, potential mining company demand for waste water effluent and possible interface of an effluent delivery facility with the proposed Central Arizona Project. The effluent resources were analyzed with respect to potential demand. An optimum alignment was selected. An optimum system was detailed through design schematics, amortized cost and finance requirements, and an implementation schedule. It was concluded that a waste water effluent delivery facility could be implemented which would utilize reclaimed effluent in quantities approximating 35 percent of basin overdraft and which would provide revenue for full cost recovery over a 20 year operation period. The mining companies are studying the internal economic impacts of the project.     

HYDROLOGIC MODELING OF TWO GLACIATED WATERSHEDS IN NORTHEAST PENNSYLVANIA1

ABSTRACT: A hydrologic modeling study, using the Hydrologic Simulation Program - FORTRAN (HSPF), was conducted in two glaciated watersheds, Purdy Creek and Ariel Creek in northeastern Pennsylvania. Both watersheds have wetlands and poorly drained soils due to low hydraulic conductivity and presence of fragipans. The HSPF model was calibrated in the Purdy Creek watershed and verified in the Ariel Creek watershed for June 1992 to December 1993 period. In Purdy Creek, the total volume of observed stream-flow during the entire simulation period was 13.36 × 10⁶ m³ and the simulated streamflow volume was 13.82 × 10⁶ m³ (5 percent difference). For the verification simulation in Ariel Creek, the difference between the total observed and simulated flow volumes was 17 percent. Simulated peak flow discharges were within two hours of the observed for 30 of 46 peak flow events (discharge greater than 0.1 m³/sec) in Purdy Creek and 27 of 53 events in Ariel Creek. For 22 of the 46 events in Purdy Creek and 24 of 53 in Ariel Creek, the differences between the observed and simulated peak discharge rates were less than 30 percent. These 22 events accounted for 63 percent of total volume of streamflow observed during the selected 46 peak flow events in Purdy Creek. In Ariel Creek, these 24 peak flow events accounted for 62 percent of the total flow observed during all peak flow events. Differences in observed and simulated peak flow rates and volumes (on a percent basis) were greater during the snowmelt runoff events and summer periods than for other times.     

SETTING AN EFFECTIVE TMDL: SEDIMENT LOADING AND EFFECTS OF SUSPENDED SEDIMENT ON FISR1

ABSTRACT: The Agricultural Drainage and Pesticide Transport model was used to examine the relationship between fish and suspended sediment in the context of a proposed total maximum daily load (TMDL) in two agricultural watersheds in Minnesota. During a 50‐year simulation, Wells Creek, a third‐order cold water stream, had an estimated 1,164 events (i.e., one or more consecutive days of estimated sediment loading) and the Chippewa River, a fourth‐order warm water stream, had 906 events of measurable suspended sediment. Sublethal thresholds were exceeded for 970 events and lethal levels for 194 events for brown trout in Wells Creek, whereas adult nonsalmonids would have experienced sublethal levels for 923 events and lethal levels for 241 events. Sublethal levels were exceeded for 756 events and lethal thresholds were exceeded for 150 events in the Chippewa River. Nonsalmonids would have experienced 15 events of mortality between 0 and 20 percent in Wells Creek. In the Chippewa River, there were 35 events of mortality between 0 and 20 percent and one event in which mortality could have exceeded 20 percent. The Minnesota Pollution Control Agency has proposed listing stream reaches as being impaired for turbidity at 25 NTU, which is approximately 46 mg suspended sediment/1. We estimated that 46 mg/1 would be exceeded approximately 30 days in a year (d/yr) in both systems. A TMDL of 46 mg SS/1 may be too high to ensure that stream fishes are not negatively affected by suspended sediment. We recommend that an indicator incorporating the duration of exposure be applied.     

ORIGIN AND TRANSPORT OF DISSOLVED CHEMICALS IN A KARST WATERSHED,SOUTHWESTERN ILLINOIS1

ABSTRACT: An extensive base of water quality information emphasizing the effects of land use and hydrology was obtained in the karstified Fountain Creek watershed of southwestern Illinois to help resolve local water quality issues. Agrichemicals dominate the loads of most water quality constituents in the streams and shallow karstic ground water. Only calcium (Ca), magnesium (Mg), Aluminum (A1), and sulfate (SO₄) ions are predominantly derived from bedrock or soils, while agrichemicals contribute most of the sodium (Na), potassium (K), chlorine (Cl), nitrate (NO₃), fluorine (F), phosphorus (P), and atrazine. Concentrations of individual ions correlate with discharge variations in karst springs and surface streams; highly soluble ions supplied by diffuse ground water are diluted by high flows, while less soluble ions increase with flow as they are mobilized from fields to karst conduits under storm conditions. Treated wastewater containing detergent residues dominates the boron load of streams and provides important subordinate loads of several other constituents, including atrazine derived from the Mississippi River via the public water supply. Average surface water concentrations at the watershed outlet closely approximate a 92:8 mixture of karst ground water and treated wastewater, demonstrating the dominance of ground water contributions to streams. Therefore the karst aquifer and watershed streams form a single water quality system that is also affected by wastewater effluent.     

Lagrangian Sampling for Emerging Contaminants Through an Urban Stream Corridor in Colorado1

Abstract: Recent national concerns regarding the environmental occurrence of emerging contaminants (ECs) have catalyzed a series of recent studies. Many ECs are released into the environment through discharges from wastewater treatment plants (WWTPs) and other sources. In 2005, the U.S. Geological Survey and the City of Longmont initiated an investigation of selected ECs in a 13.8‐km reach of St. Vrain Creek, Colorado. Seven sites were sampled for ECs following a Lagrangian design; sites were located upstream, downstream, and in the outfall of the Longmont WWTP, and at the mouths of two tributaries, Left Hand Creek and Boulder Creek (which is influenced by multiple WWTP outfalls). Samples for 61 ECs in 16 chemical use categories were analyzed and 36 were detected in one or more samples. Of these, 16 have known or suspected endocrine‐disrupting potential. At and downstream from the WWTP outfall, detergent metabolites, fire retardants, and steroids were detected at the highest concentrations, which commonly exceeded 1 μg/l in 2005 and 2 μg/l in 2006. Most individual ECs were measured at concentrations less than 2 μg/l. The results indicate that outfalls from WWTPs are the largest but may not be the sole source of ECs in St. Vrain Creek. In 2005, high discharge was associated with fewer EC detections, lower total EC concentrations, and smaller EC loads in St. Vrain Creek and its tributaries as compared with 2006. EC behavior differed by individual compound, and some differences between sites could be attributed to analytical variability or to other factors such as physical or chemical characteristics or distance from contributing sources. Loads of some ECs, such as diethoxynonylphenol, accumulated or attenuated depending on location, discharge, and distance downstream from the WWTP, whereas others, such as bisphenol A, were largely conservative. The extent to which ECs in St. Vrain Creek affect native fish species and macroinvertebrate communities is unknown, but recent studies have shown that fish respond to very low concentrations of ECs, and further study on the fate and transport of these contaminants in the aquatic environment is warranted.     

HYDROLOGIC EFFECTS OF THE TONKAWA CREEK FLOOD ABATEMENT PROGRAM1

ABSTRACT: Floodwater-retarding impoundments, controlling 68 percent of the drainage area of Tonkawa Creek, a Washita River tributary in southwestern Oklahoma, have reduced the total flow volume about 36 percent over a 5-year period. Analyses showed the reduction occurred primarily in the less-than-2.5-cfs flow range, indicating the base flow regime has been altered. However, channelizing the downstream, mild-sloped, 3.6 miles of Tonkawa Creek that flows across a Washita River terrace increased the flow volume fourfold at the outlet. A double-masscurve analysis of water yield from a 1,127-square-mile Washita basin segment versus an untreated tributary showed the yield has not changed after 25 percent of the tributary area had been treated. Therefore, the flow reduction caused by structures is being offset by increased yields from channelization.     

EFFECTS OF ADVANCED WASTEWATER TREATMENT ON THE QUALITY OF WHITE RIVER,INDIANA1

ABSTRACT: In 1983, the City of Indianapolis, Indiana, completed construction of advanced wastewater treatment (AWT) systems to enlarge and upgrade its existing Belmont Road and South port Road secondary treatment plants. A nonparametric statistical procedure, a modified form of the Wilcoxon-Mann-Whitney rank-sum test, was used to test for trends in water quality at two upstream and two downstream sites on White River and at the two treatment plants. Results comparing the pre- (1978–1980) and post- (1983–1986) AWT periods show statistically significant improvements in the quality of the treated effluent and of the White River downstream from the plants. Water quality at sites upstream from the city was relatively constant during the period of study. Total ammonia (as N) decreased 14.6 mg/L and BOD₅ (five-day biochemical oxygen demand) decreased 10 to 19 mg/L in the two effluents. Total ammonia in the river downstream from the plants decreased 0.8 to 1.9 mg/L and BOD₅ decreased 2.3 to 2.5 mg/L. Nitrate (as N) increased 14.5 mg/L in the plant effluents and 2.0 to 2.4 mg/L in the river because of in-plant nitrification. Dissolved oxygen concentration in the river increased about 3 mg/L because of reduced oxygen demand for nitrification and biochemical oxidation processes.     

EFFECTS OF LOMA PRIETA EARTHQUAKE ON SURFACE WATERS IN WADDELL VALLEY1

ABSTRACT: Waddell Creek is a perennial stream near Santa Cruz, California, which discharges into the Pacific Ocean about 38 km from the epicenter of the Loma Prieta earthquake (October 17, 1989, M 7.1). The earthquake caused no significant changes or damage to structures or surface features in the area, but was followed by an order of magnitude transient increase in discharge of Waddell Creek and nearby springs. The transients approximate a step rise followed by an exponential recession with time constants of from 37 to 59 days. The flow recession pattern of Waddell Creek was obscured by heavy rains after about 50 days; however, the springs maintained an exponential recession with minimal rain interference for periods of several time constants, then abruptly ceased flowing. A comparison of the pre-quake and post-quake chemical signature of one of the springs shows only minor changes in water chemistry indicating a common source for pre- and post-quake waters. Increased permeability of the subsurface ground material appears to be the most probable cause of the hydrologic changes. Post-seismic reduction of permeability has not been observed or inferred.     

DEEP WELL DISPOSAL OF SECONDARY EFFLUENT IN DADE COUNTY,FLORIDA1

ABSTRACT: Data were obtained from drilling and testing of a test injection well for deep underground injection of waste water effluent from the proposed 50-million-gallon-per-day (mgd) South District Regional Wastewater Treatment Plant of the Miami-Dade Water and Sewer Authority, Dade County, Florida. The drilling operation progressed in stages, each stage coverting the strata to be sealed off by the 48-inch, 40-inch, 30-inch, and 20-inch casings, respectively. Total depth of the well is 3,200 feet. The top of the saline, cavernous, dolomitic Boulder Zone was found at 2,790 feet below the surface and is separated from the Floridan aquifer above by approximately 1,100 feet of confining limestone layers. These confining layers were determined, by packer testing, to be very effective. The transmissivity of the Boulder Zone was estimated to be 14 × 10⁶ gallons per day per foot (gpd/ft) from the data obtained from pump out tests. An 8,000-gallon-per-minute (gpm) injection test was conducted to confirm well performance under operating conditions. Based on all of the data obtained, it was concluded that underground injection into the Boulder Zone of secondary waste water effluent from the proposed treatment plant is feasible, both hydraulically and environmentally. A monitoring system was proposed to provide a record of the effects of injection on the subsurface environment.     

INFLUENCES OF A FOREST ON THE HYDRAULIC GEOMETRY OF TWO MOUNTAIN STREAMS1

ABSTRACT The influence of a forest on the formation of steps in two small streams of the Colorado Rocky Mountains was studied. Steps provided by logs fallen across the channel added to flow energy reduction. The streams required additional gravel bars to adjust to slope. Average step length between logs and gravel bars was strongly related to channel gradient and median bed material size. Based on the average number of log steps per 50 feet of channel, an average of 116 percent of gravel bars were added at Fool Creek and 60 percent at Deadhorse Creek. The latter had 52 percent more logs in the channel and therefore required less bed material movement than the former. Although these are “rushing mountain streams,” most flow velocities ranged between 0.5 and 2.5 f.p.s. Exponents of a function relating rate of change of depth or velocity to discharge indicated that dynamic stream equilibrium was attained. Implications for forest management are that sanitation cuts (removal of dead and dying trees) would not be permissible where a stream is in dynamic equilibrium and bed material movement should be minimized.