Impact of Proposed Radon Drinking Water Regulations on Groundwater Systems in California
This summer, the Environmental Protection Agency is expected to propose a maximum contaminant level (MCL) of 300 pCi/l for radon in drinking water. This anticipated MCL, if adopted, will...
Autothermal Thermophilic Aerobic Digestion: A Two-Year Appraisal of Canadian Facilities
Full scale, autothermal thermophilic aerobic digestion (ATAD) facilities were constructed or upgraded in 1988 to demonstrate high temperature aerobic digestion of municipal sludges at...
Pilot-scale Trickling Filter Nitrification at the Longmont WWTP
Nitrification rates in trickling filters can be affected by influent organic matter, filter length, and hydraulic loading rate. The effects of these parameters on nitrification rate were...
Aerobic Denitrification in Activated Sludge
Definitive proof of the phenomenon of concurrent biological nitrification-denitrification in activated sludge is presented. The mechanism appears to be an inhibition of oxygen respiration...
Crossflow vs. Counterflow Air Stripping Costs
Crossflow towers offer a potential economic advantage over counterflow towers due to savings in fan power costs as well as material costs. These savings increase as contaminant volatility...
Air Stripping of Refinery Effluent for TC Compliance
In order to manage the risk that the water effluent may at times exceed the limits of the USEPA final Toxicity Characteristics (TC) rule which came into effect on September 25, 1990, a...
Complete Recyling in the Organics Chemicals Industry
Regulations for both direct and indirect discharges have become so stringent in order to protect the environment that wastewater treatment and effluent levels in the organics chemicals...
Waste Minimization/Reduction Initiatives and Consequences
This paper summarizes the various waste minimization and waste reduction initiatives being implemented nationwide. Areas of evaluation include: Material Substitution, Production Modification,...
Practical Use of Plants for Water Purification
Problems with contaminated wastewater in USA, Eastern Europe, and developing countries are outlined. Botanical sewage purification for purifying human, animal, and industrial sewage is...
Constructed Wetlands at Mesquite, Nevada
Subsurface flow (SF) wetlands are used to provide effluent polishing following treatment in an aerated lagoon at Mesquite, Nevada. General SF wetland design methodology is discussed in...
Reliability-Based Estimates of Wetland Detention Times for Wastewater Treatment
Determination of the hydraulic residence or detention time is often the first step in design of wetlands constructed for wastewater treatment. Current methods for estimating wetland detention...
Inventory of Constructed Wetlands for Municipal Wastewater Treatment in the U.S.
The U.S. EPA's Risk Reduction Engineering Laboratory is conducting an inventory of constructed wetlands (CW) for municipal wastewater treatment in the U.S. The inventory is...
Design Considerations for Control of Volatile Organic Compounds at Wastewater Treatment Facilities
New federal and state regulations require publicly owned treatment works (POTW's) to consider emissions of volatile organic compounds (VOC's) as potentially significant...
Continuing Effort to Eliminate Odors at Orange County's Wastewater Treatment Plants
The County Sanitation Districts of Orange County (CSDOC), California own and operate two wastewater treatment plants. Reclamation Plant No. 1, in Fountain Valley, treats approximately...
Influence of Moisture Influx on the Hygro-thermal Performance of a Clay Buffer Developed for Nuclear Disposal Vault
This paper focusses on an experimental study that investigates the heat transfer and moisture movement within a bentonite clay buffer compacted in a borehole located in a granite block....
Permeability of Cement Grout Plugs in Basaltic Rocks
Flow tests have been conducted on expansive cement grout plugs with diameters of 160 mm and 200 mm, and length-to-diameter ratios of one, in boreholes in basalt blocks, and in steel pipes....
Results of the Engineering Special Studies for the UMTRA Project?FY90
The proposed U.S. Environmental Protection Agency (EPA) groundwater standards (40 CFR 192) require that Uranium Mill Tailings Remedial Action (UMTRA) Project remedial action designs meet...
Modeling Analysis of CSO Impacts in a Tidal Basin
Short duration intensive inflows of combined sewer overflows (CSO) to marine tidal basins create stratified water quality for limited periods of time. Accurate assessment of water quality...
Assessment of Effects of a Water Supply Withdrawal on Downstream Flows for Anadromous Fish Reproduction
A BASIC computer model was developed to simulate reservoir operations in conjunction with a proposed water supply withdrawal. The model was used to assess the potential impacts of the...
Using Multiple Water Quality Models for Determining Variable Emission Levels for Wasteload Allocation
We present a methodology for determining the least-cost wasteload allocations from multiple point sources discharging into a single water body. The system of point sources is modeled as...
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