Physical Sciences and Mathematics Commons^™

Interagency Lake Mead And Las Vegas Wash Monitoring Program: Standard Operating Procedures Manual, Bureau Of Reclamation, City Of Henderson Water Reclamation Facility, City Of Las Vegas Water Pollution Control Facility, Clark County Sanitation District, Nevada, Southern Nevada Water Authority

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A number of agencies sample Lake Mead and the Las Vegas Wash on a routine basis at several locations. In order to share and properly interpret the data, the Bureau of Reclamation, Southern Nevada Water Authority and the three Wastewater Treatment Facilities (City of Las Vegas, Clark County Sanitation District and City of Henderson) formed a committee to examine sampling and analytical protocols and to share information with the goal of maximizing the data quality. The group first met in April 1997.

It was agreed that an effort should be made to discuss and compare specific sampling and analytical techniques …

The Influence Of The Wastewater Drainage From The Las Vegas Valley On The Limnology Of Boulder Basin, Lake Mead, Nevada-Arizona, James F. Labounty, Michael J. Horn, Bureau Of Reclamation

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Lake Mead, Colorado River, Arizona-Nevada, is one of the most heavily used reservoirs in the western United States, providing abundant recreational opportunities as well as downstream domestic and agricultural water for over 22 million users. Based on average nutrient levels and productivity, Lake Mead is classified as mildly mesotrophic. The interflow of the Colorado River dominates the limnology of much of the 106 km-long reservoir, and may still be identified at Hoover Dam under certain conditions. The lower basin of Lake Mead ending at Hoover Dam is known as Boulder Basin and is near the Las Vegas metropolitan area. Las …

Report Of Significant Findings--Las Vegas Bay/Boulder Basin Investigations, James F. Labounty, Michael Horn, Bureau Of Reclamation

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Field sampling was carried out between 0830 and 1500 beginning at the confluence of Las Vegas Wash and the Inner Las Vegas Bay. Ten (10) locations were sampled, each in a similar manner. Locations of sampling stations are in line from the Wash-Bay confluence to a point midway between Saddle and Black Islands. In addition, sampling was done at a location midway between Sentinel Island and the base of Fortification Hill, and at the buoy line in front of Hoover Dam. Sampling stations are labeled from LV01, at Wash-Bay confluence, to LV17 at Hoover Dam. A significant data collection point …

Nutrient Limitation In A Southwestern Desert Reservoir: Eutrophication Of Las Vegas Bay, Lake Mead, Nevada, Davine M. Lieberman

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Algal bioassay tests were conducted with Selenastrum capricornutum and natural algae on inner Las Vegas Bay, Lake Mead, Nevada, from December 1992 through September 1993, to identify any nutrient limitation in an area of the reservoir that has experienced problems associated with severe nutrient enrichment. Three areas were sampled based on a gradient of water quality conditions that existed in Las Vegas Bay (LVB). Disodium ethylenedinitrilotetraacetate (EDTA) significantly stimulated algal growth compared to non-EDTA treatment. Algal bioassays indicated that phosphorus (P) was the primary limiting nutrient at all stations for most of the test dates. Chl a response with EDTA …

Study Of Existing Information Concerning Water Quality Within Lake Mead, Vicki Scharnhorst, Southern Nevada Water Authority

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The purpose of Task 010A15M of the Southern Nevada Water Authority (SNWA) Treatment and Transmission Facility (TTF) contract is to conduct a study of existing information concerning water quality within Lake Mead and identify additional water quality studies that are needed to supplement existing data.

The objective of this task is not to discuss treatability of the raw water source; this is addressed by Task 010A18M, "Define Water Treatment Requirements." In addition, a narrative on the effect of pending Safe Drinking Water Act amendments and a determination of treated water quality goals is included in Task 010A16M, "Review Safe Drinking …

Total Maximum Daily Loads And Waste Load Allocations For Las Vegas Bay: Rationale And Calulations, State Of Nevada: Division Of Environmental Protection

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In September 1987 the Nevada Division of Environmental Protection revised Water Quality Standards for Las Vegas Wash (LVW) and Lake Mead. Standards were set for chlorophyll-a and unionized ammonia in Las Vegas Bay (LVB) (NDEP 1987). The 1986 and 1987 LVB data showed non-achievement of both the chlorophyll-a and unionized ammonia standard which triggered an analysis of total phosphorus and total ammonia Total Maximum Daily Loads and Waste Load Allocations which are presented in this report.

This report is separated into three sections:

1. 1987 Las Vegas Bay Water Quality Conditions and Seasonal Periodicity.

2. Concentration Estimates at Northshore Road …

Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation

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A pumped storage system consists of an upper reservoir and lower reservoir separated by an elevation difference. During low demand energy periods such as nights and weekends water is pumped from the lower to the upper reservoir using available energy from conventional steam electric power plants. During high energy demand periods, such as mornings and afternoons of weekdays, upper reservoir water is allowed to drop back down through the same system of water conduits and turbines, generating electricity to conveniently meet abrupt electrical energy requirements. The same water turbines thus act both as pumps and as conventional hydroelectric turbines.

Because …

River Discharge Study, Laughlin, Nevada: Colorado River Model And Diffusion Study, B. Dennis Hugh, David L. Stringfield, Jill C. Bicknell, Robert A. Ryder, Clark County Sanitation District, Nevada

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A water quality modeling study of the Mohave Reach of the Lower Colorado River (from Davis Dam to the Nevada/California Stateline) was conducted to evaluate potential water quality impacts resulting from a proposed Laughlin, Nevada wastewater effluent discharge. The study included four major components: (1) review of the current regulatory framework; (2) a field data collection program to document existing water quality conditions in winter, summer, and fall; (3) development and verification of far-field and near-field (mixing zone) water quality models; and (4) application of the models to project future river quality conditions for several treatment-discharge alternatives as well as …

River Discharge Study, Laughlin, Nevada: Field Survey Data, 1987, B. Dennis Hugh, David L. Stringfield, Jill C. Bicknell, Robert A. Ryder, Clark County Sanitation District, Nevada

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A report of the first field data collection effort for the Laughlin River Discharge Study, conducted by Kennedy/Jenks/ChiIton in February, 1987, on the Mohave Reach of the Colorado River. This report also serves to transmit the laboratory analysis reports for all of the analyses performed and summary tables of the results.

This report is organized as follows:

1. Field Conditions and Methodology

2. Summary of Sampling and Analysis Results

3. Deviations from the Proposed Sampling Program

4. Recommendations for Future Sampling

5. Attachments:

A. Climatological Data

B. Davis Dam Average Hourly Releases

C. Laboratory Analysis Reports

Lake Mead Prefertilization Study: Preliminary Nutrient Enhancement Studies In Lake Mead, Richard P. Axler, Larry J. Paulson, Patrick J. Sollberger, Donald H. Baepler, U.S. Bureau Of Reclamation

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Studies conducted by the University of Nevada-Las Vegas (UNLV), the Nevada Department of Wildlife (NDOW), the Arizona Game and Fish Department (AGFD), The Nevada Division of Environmental Protection (NDEP), and the United States Bureau of Reclamation (USBR) have identified decreased algal production as a major factor involved in the decline of the Lake Mead sport fishery. Phosphorus-laden silt particles in the Colorado River have been sedimenting out in Lake Powell since the completion of Glen Canyon Dam 286 miles upstream in 1963. This sharp decrease in phosphorus loading to Lake Mead (>5000 tons per year) has resulted in decreased …

Analysis Of The Water-Quality Standards Proposed By The Nevada Division Of Environmental Protection, City Of Las Vegas, Nevada

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The Nevada Division of Environmental Protection (DEP) has proposed water-quality standards, applicable to Las Vegas Bay and Lake Mead, for (1) chlorophyll, (2) un-ionized ammonia, and (3) pH.

We have concluded that the proposed standards are unlikely to protect or improve water quality in Lake Mead. The proposed chlorophyll standard:

May harm the fishery. Lakes with more chlorophyll have greater fish production.

Will not improve clarity. Chlorophyll concentrations above 30 ug/1 have little effect on clarity.

Will not protect against scums or dominance by blue-green algae. Lake Mead shows no consistent relationship between chlorophyll and scums or blue-green dominance.

Will …

Las Vegas Wash And Lake Mead Proposed Water Quality Standards: Revisions And Rationale, State Of Nevada: Division Of Environmental Protection

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Rationale of review and for proposed changes to the Nevada Pollution Control Regulations (NAC 445.1354, 445.1355, 445.1356, 455.1367, 445.1352, 445.1353, 445.1350, 445.1351) before the State Environmental Commission on June 23 and 24, 1987.

A Proposal To Fertilize The Overton Arm And Gregg Basin Areas Of Lake Mead, Larry J. Paulson

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Several limnological studies have been conducted in Lake Mead during the past decade. The recent studies clearly show that most of Lake Mead is deficient in nutrients, especially phosphorus, and very low in productivity. The reservoir-wide average total phosphorus concentration for 1981 - 1982 was only 9 mg/m³. This is below levels found In most oligotrophic lakes and reservoirs. Algal biomass, as measured by chlorophyll-a, averaged only 1.5 mg/m³. That also places Lake Mead in the oligotrophic range. Transparency, as measured by a Secchi disc, averaged 9-5 m in Lake Mead during 1981-1982. That far exceeds …

Seasonal And Spatial Heterogeneity In The Limnetic Zooplankton Community Of Lake Mead, Gene Robert Wilde

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Zooplankton samples collected from throughout Lake Mead, in 1981-1982, demonstrate the presence of a statistically significant seasonal and spatial heterogeneity in zooplankton densities. Seasonally, the major zooplankton groups were most abundant in the spring and fall, coincident with maxima in chlorophyll-a concentrations. Successions among the various rotifers, cladocerans and copepods present in the reservoir were influenced by food availability, diapause, predation by planktivorous fish and, possibly, water temperatures.

Spatial heterogeneity in zooplankton densities was unrelated to water temperature, pH, conductivity and dissolved oxygen concentrations, but was related to the abundance of phytoplankton (chlorophyll-a concentrations) and fish. Statistical analyses indicate that …

An Ecological Analysis Of Relic Diatoms In Sediments Of Las Vegas Bay, Lake Mead, David Ross Hetzel

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Relic diatoms in sediments of the inner Las Vegas Bay, near the Las Vegas Wash sewage inflow, were examined in order to assess historic trophic conditions in this area of Lake Mead. Diatom sedimentation rates and ratios of Araphidineae/Centrales (A/C) diatom groups were determined from sediment cores collected in the old wash channel 1.5 km from the sewage inflow (station 2), in a small cove 1.5 km further downstream (station 3) and in an adjacent embayment off Gypsum Wash (station 4). Diatom sedimentation rates generally increased from the bottom to the top of each core, but pronounced minima existed at …

Methods For Biological, Chemical, And Physical Analyses In Reservoirs, Penelope E. Kellar, Sherell A. Paulson, Larry J. Paulson

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This manual contains detailed descriptions of biological, chemical and physical sampling and analytical procedures used at the Lake Mead Limnological Research Center. The manual was prepared in response to requests made by numerous individuals involved in the Las Vegas Valley Water Quality Program. This manual represents what we consider to be a reasonably complete compilation of methods useful in studying both general and specific limnological questions. While each section is sufficiently detailed to be of use to investigators with little experience in limnological methodology, the methods can be used on a wide variety of lakes and reservoirs, with relatively little …

The Limnological Status Of Lake Mead And Lake Mohave Under Present And Future Powerplant Operations Of Hoover Dam, Larry J. Paulson, John R. Baker, James E. Deacon, U.S. Water And Power Resources Service

Publications (WR)

The ever-increasing demand for energy in the southwest has led to a search for additional sources of power generation. Coal-fired powerplants currently provide most of the baseline energy in the southwest, but this must be supplemented with hydroelectric power during periods of peak demand. In order to provide additional peaking power, the U.S. Bureau of Reclamation is considering a number of projects to modify existing hydroelectric facilities, or add new facilities in the Lake Mead Recreation Area.

The Hoover Powerplant Modification Feasibility Investigation was authorized by Congress on December 16, 1975 to determine the feasibility of: (i) adding one or …

Seasonal And Spatial Variation In Primary Productivity In Boulder Basin, Lake Mead, Clark County, Nevada, Isamu Aoki

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The ¹⁴C light and dark bottle technique for measurement of primary production was utilized as a means of assessing the amount of inorganic carbon being converted Into organic form by the photosynthesis of phytoplankton populations In the Boulder Basin of Lake Mead.

Spatial and time series changes of productivity levels observed at eight sampling locations within Boulder Basin Indicate that the Influence of treated municipal arts' industrial effluent flowing into Les Vegas Bay is contributing high levels of available nutrients at Las Vegas Wash Inlet to cause productivity to approximate those levels associated with polluted waters.

Productivity levels at …

Phytoplankton Successions And Lake Dynamics In Las Vegas Bay, Lake Mead, Nevada, Ervon R. Koening, Richard W. Tew, James E. Deacon

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Phytoplankton successions, applications of the general growth equation, and physical measurements have been employed to investigate events occurring at the interface between industrial and sewage effluent contained in Las Vegas Wash and the waters of Lake Mead, Nevada. The data indicate that the entering waters tend to form a density current interrupted at intervals by dynamic effects generated in the lake. The dynamic relationships described here for the spring months suggest that a much more thorough understanding of physical, chemical and biological interactions is necessary to permit solution of the numerous problems of Las Vegas Bay discussed or alluded to …

A Mathmatical Model Of Primary Productivity And Limnological Patterns In Lake Mead, Lorne G. Everett

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The temporal and spatial changes in chemical and biological properties of Lake Mead have been investigated, thereby indicating the sources of water pollution and the time of highest pollution potential. Planktonic organisms have been shown to indicate the presence of water problems. Macro- and micro-nutrient analyses have shown that primary productivity is not inhibited by limiting concentrations. A mathematical model has been developed, tested with one set of independent data, and shown worthy of management utility. Although the model works very well for the Lake Mead area, the physical reality of the Multiple Linear Regression equation should be tested on …

Report On Water Pollution Problems In Las Vegas Wash And Las Vegas Bay, Environmental Protection Agency

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This report was prepared by the Federal Water- Quality Administration, Pacific Southwest Region, now the Environmental Protection Agency (EPA), Region IX, at the request of the State of Nevada, Department of Health, Welfare, and rehabilitation. In a letter, dated December 5, 1969, this agency asked for technical assistance, as authorized by the Federal Water Pollution Control Act, in developing discharge standards appropriate for Las Vegas Bay, Lake Mead, and the Lower Colorado River. The subsequent study was performed by EPA from January through August, 1970. The establishment of Nevada State Water Quality Standards for these waters will enable responsible officials …

A Conceptual Draft Of A Dynamic Hydro-Biological Model For Lake Mead, L. G. Everett, Bureau Of Reclamation

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Food and energy transformation in an aquatic system must be understood in order to develop a simulation approach. This report provides a comprehensive study of an aquatic ecosystem. The objectives of this report are to show:

(1) the biological relationships in an aquatic system

(2) the role of nutrients in the biological cycle

(3) the role of abiotic factors in a limnetic environment

(4) the status of the art of "Eutrophication modeling".

The Effect Of Las Vegas Wash Effluent Upon The Water Quality In Lake Mead, D. A. Hoffman, P. R. Tramutt, F. C. Heller, Bureau Of Reclamation

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This study developed from observations made during an earlier study on Lake Mead which was reported in CHE-70, Water Quality Study of Lake Mead. Results from that study indicated that poor-quality water was flowing into the Las Vegas Bay reach of Boulder Basin, Lake Mead. Also reports of deteriorating water quality, resulting in taste and odors in domestic water supplies taken from Boulder Basin as well as a reduction in the attractiveness of Las Vegas Bay for recreational uses caused by aquatic plants and algae blooms, indicated a need for a concentrated study concerning the effects of flows from Las …