Geostatistics in Estimating Chemical Residuals at a Site
Kriging with generalized covariances is used to evaluate the effectiveness of remediation and cleaning of a contaminated site. The goal is to estimate: a) the amount of total volatile...
Odors: The Other Effluent
Neighbors object to unpleasant odors emitted at wastewater treatment plants, and dealing with such odors requires tact as well as technology. The operators and engineers must listen to...
Stabilizing a `Mann'-Sized Sinkhole
On Sept. 21, 1988, a sinkhole suddenly developed beneath a transmission/distribution effluent pipeline on Mann Road in Orange County, FL. Initially it measured 30 ft in diameter and 8...
Studies of Fish Protection Methods at Hydroelectric Plants
Five largely untested but economical fish-protection systems were tested at sites throughout North America. The process of selecting laboratory and field test sites was completed at the...
Waterstop Technology?The Next Chapter
Water leakage through and around failed waterstops in concrete structures can cause serious flooding, damage to equipment, affect structural stability, and pose potential safety problems....
Alternating Direction Oxidation Ditches?A Cost Saving Technology from Denmark
A soon to be released EPA report claims that in Denmark, small alternating direction oxidation ditches (ADOD) save as much as 70% of the cost for conventional oxidation ditches. The alternating...
Foam Over Troubled Toxics
Foams are now being used to control noxious vapor emissions from hazardous waste landfills. Another use of foams is in control of vapors emitted by chemical spills and fires. This article...
Speaking of RISK
With sensitivity, common sense and preparation, an engineer can explain risk effectively and fairly without alienating the public. Risk communicators should use a standard set of terms...
Lead: Taking it from the Tap
Medical evidence is lowering the definition of a safe concentration of lead. In turn, there has been an effort to reduce lead in drinking water. Solutions are complicated, as many lead...
The Nebraska Chemigation Cat?1987 in Review
The Nebraska Chemigation Act was signed into law in April of 1986 with requirements effective January 1, 1987. The Act is one of the most comprehensive pieces of chemigation legislation...
Chemigation Backflow Prevention Assemblies
Chemigation with sprinkler irrigation systems is widely used throughout the United States. One potential environmental hazard of this practice is the point source water contamination due...
Advanced Chemigation Systems for Environmental Safety and Groundwater Protection
A multifunction irrigation system has been developed which utilizes a separate dynamic in-canopy nozzle system for chemical application. Testing the system with a lithium tracer on four...
Potassium Fertigation in Drip Irrigated Peppers in Puerto Rico
Three potassium fertigation rates (T1 = 100%, T2 = 60%, T3 = 30%) via trickle irrigation, fertilization rates (T4 = 100%, S1 = 100%, S2 = 50%, S3 = 0.0) and nonfertilization (T5 = 0.0)...
Variability of Copper in the International Reach of the Similkameen River, British Columbia
All total copper concentrations measured in soft water during spring freshets were above the Canadian Water Quality Guidelines. Approximately 57% of all 108 observations over the three-year...
Adsorption, Desorption and Transport of Pesticides in Groundwater: A Critical Review
Adsorption and desorption are major mechanisms affecting the transport and fate of pesticides in groundwater. Equilibrium, chemical nonequilibrium and physical nonequilibrium adsorption...
Riverbank Instability Due to Bed Degradation
Degradation lowers the bed of an alluvial channel over a long reach. This has the effect of increasing the bank heights and angles, which decreases the stability of the banks with respect...
Carbonyl Extraction of Lunar and Asteroidal Metals
The century-old Mond process for carbonyl extraction of metals from ore shows great promise as an efficient, low energy scheme for producing high-purity Fe, Ni, Cr, Mn, and Co from lunar...
Oxygen Production for a Future Lunar Base
This paper discusses various ways for providing oxygen for a lunar base. Currently, there are three methods available which are technologically possible. One of these is the use of chemical...
Out of the Mainstream
By treating only part of the wastewater stream, a biological/chemical phosphorus removal system also reduces chemical costs and sludge production. The system consists of two 60 ft dia...
Program to Reduce Deicing Chemical Usage
Over the years (since about 1948), the dependency on deicing chemicals has been increased to provide 'bare pavement' for safe and efficient winter transportation....
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