Clean Water at the Crossroads
Thirty years after the passage of the Clean Water Act, the quality of effluent from the nation's wastewater treatment plants has improved considerably. However, much of the...
A Tale of Two Bids
In early 1992, the Escambia County Utilities Authority determined that its 2 mgd Avondale Wastewater Treatment Plant should be expanded to 8 mgd to meet the growing needs of the Pensacola,...
Tunneling Under Pressure
Work will begin this month on the South Bay Ocean Outfall (SBOO) project, a $140 million undertaking to build 3.6 mi of tunneling through the saturated ground of the Pacific Ocean. When...
Pilot Testing of a Zero-Discharge Treatment Process
As environmental regulations become more stringent, pulp and paper mills are investigating alternatives to conventional biological treatment and discharge of effluents into receiving waters....
Dynamic vs. Quasi-Static Effluent Limits
Selenium water quality objectives are currently being exceeded in the San Joaquin River, California due to agricultural subsurface drainage discharges. The Federal Clean Water Act requires...
Fluidized Bed Denitrification of Secondary Effluent during Wastewater Reclamation in Southern California
A pilot scale fluidized bed denitrification bioreactor was operated for a period of three years as one unit process in a series designed to repurify secondary effluent for subsequent indirect...
Automatic Control of Flocculation Processes
A control system for flocculation, used in water and wastewater treatment operations is being developed. The approach is based on detailed particle size distribution measurements of influent...
Salinity and Hydraulic Issues at a Constructed Wetlands
A constructed wetlands at Boulder City, Nevada was designed to use effluent pumped from the City's wastewater treatment plant. The design was complicated by the highly permeable...
Biological Serendipity from an Ocean Outfall Maintenance Inspection
A large deep-water ocean outfall discharging ?880 x 106 liters day (230 million gallons day of treated wastewater effluent was inspected with a one-man...
Effects of Sewage Effluent Irrigation on Paddy
Paddy, the staple food of South India, occupies about an area of 38 million hectares in India [1, 1987]. Being a semi-aquatic plant, its water requirements are many times more than most...
Impact of Point and Nonpoint Discharges on the Water Quality of a Reach of the Red River of the North
Projected increase of discharge of point and nonpoint-source effluents into rivers, make compliance with water quality standards increasingly difficult and necessitate controlling these...
Comparison of Worst-Case and Probabilistic Approaches to Ocean Outfall Mixing Zone Analysis
Two approaches have been used for ocean outfall mixing zone analysis: worst-case approach and probabilistic approach. This paper discusses some advantages and disadvantages of the worst-case...
Near Field Modeling
Results of near field modeling of the wastefield formed by the Sand Island, Honolulu, ocean sewage outfall are presented. Over 20,000 simulations were run with the mathematical model RSB...
East River Modeling of Water Quality for Multiple-Project Assessments
The East River Model (ERM), which employs the RMA-2V hydrodynamic and RMA-4 water quality modeling code, was used by Lawler, Matusky & Skelly Engineers to assess water quality...
Modeling Initial Mixing of Ocean Wastewater Discharges to Develop Toxic Effluent Limitations
The UM model, released by USEPA in 1992, was utilized to simulate the initial mixing of a discharge to the Atlantic Ocean near Ocean City, New Jersey. The study included field verification...
Cryptosporidium and the Milwaukee Incident
In early 1993, Milwaukee, Wisconsin reported a sharp increase in the number of diarrhea patients and shortage of over the counter drugs for diarrhea control at local pharmacies. This increase...
Clarifier Enhancements Yield Excellent Performance
The critical role of final clarifiers in meeting effluent permit requirements in indisputable. Poor performance of the final clarification step may adversely affect effluent quality. Experience...
Optimization Studies of Anaerobic Expanded Bed Reactor Pretreatment of Domestic Wastewater
In recent years the advent of the anaerobic expanded bed reactor (AEBR) has made possible the treatment of wastewaters of comparatively lower strength than have traditionally been treated...
Measurement and Automatic Control of Chlorination
Chlorination is perhaps the most commonly utilized process for wastewater effluent disinfection. In Houston's plants sodium hypochlorite solution (bleach) is mixed with secondary effluent...
Model of an Upgrade
As further studies and more extensive computer models help engineers better understand the workings of wastewater treatment plant processes, those engineers are finding more efficient...
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