Over the past few years more data and anecdotes have become available to illustrate the exact
nature of electrical injury or death. While the hazards from direct contact are widely known,
lesser understood is the injury potential from proximity to a fault event. The National Electrical
Code (NEC), Underwriters Laboratory (UL), and Occupational Safety and Health Administration
(OSHA) have recognized this hazard and implemented codes and standards to address this.
However, many water and wastewater utilities may not be aware of these requirements.
This paper examines basic safe practices a water and wastewater facility is required to implement
to minimize accident potential. Not only will this help a facility to protect staff from injury, but
it can help to prevent equipment outages that could cripple a utilities ability to treat water.
This paper is intended to be introductory in nature, and is not intended to be a working guideline
for an arc flash mitigation plan. Only a proper detailed engineering analysis of a utility can help
to develop a plan.
This paper is divided into four different interrelated areas. The first is an overview of arc flash,
its associated hazards, and what can happen when they are not addressed properly. The second
part illustrates what a municipalitie’s responsibility is, what it takes to fulfill these obligations,
and the challenge small municipality’s face. The third is the determination of what tools and
protective clothing (PPE) are required to protect workers from hazards, as well as safe working
distances. The fourth section looks at equipment and maintenance techniques that help minimize
Posted: May 20th, 2011 | Filed under: Electric, Waste Water Treatment, Water Treatment | Tags: Arc Flash Minimization, Employee Protection, Hazard Minimization, Improved Health Safety, Improved Training, Increased Education, Minimized Accident Potention | No Comments »
In 2004 JEA (the electric and wastewater utility in Jacksonville, FL) was receiving more residuals than the Buckman wastewater treatment plant (Buckman or WWTP) was able to process. Buckman treats approximately 32 mgd of wastewater through a combination of primary and advanced secondary treatment. The plant also processes sludge produced at 15 other plants from the combined treatment of an additional 47 mgd of wastewater for a total sludge production associated with treatment of roughly 80 mgd. In 2004, the thermal dryer system was overloaded and the anaerobic digestion system was being operated at near washout conditions. These issues required development of short term, cost-effective strategies to bring the BRBMF under control. The rapid population growth in JEA’s service territory and the potential to assume the operation of 4 to 5 mgd of
additional capacity in some new JEA WWTPs made the need to develop midand long-range strategies apparent. In response, JEA convened a “Blue Ribbon Panel” of sludge treatment/biosolids experts from selected consulting firms and various divisions within JEA; this panel was organized similarly to the highly successful expert group that developed the utility’s biological nutrient removal (BNR) strategies. The Biosolids Blue Ribbon Panel included John Willis and Ted Hortenstine of Brown and Caldwell; John Donovan and Richard Moore of CDM; Michael Bullard and Pat Davis of Hazen and Sawyer; and as well as Scott Schultz, Scott Kelly, Colin
Groff and David Kowalski from JEA. This paper summarizes some identified improvements that were implemented on a fast track basis by JEA staff; results from a digester investigation by Brown and Caldwell; and identified
the next steps to further alleviate JEA’s solids handling limitations. The digestion evaluation has identified means to increase Buckman’s overall digestion MCRT from less than 10 days to between 25 and 35 days for an extremely cost effective investment of roughly $1 million.
Posted: May 3rd, 2011 | Filed under: Electric, Sanitary Sewer, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Improved Thermal Drying, Plant Optimization, Plant Sustainability, Reduced Carbon Footprint, Reduced Greenhouse Gas Emissions | No Comments »
This paper will describe the results achieved by applying a Model Predictive Control (MPC) system to an Activated Sludge Plant (ASP) in the UK, with the objective of reducing energy consumption, whilst maintaining compliance within permitted environmental standards. Installation of the MPC system was initially an R&D project to assess if the suppliers performance expectations were valid. The successful outcome of the trial allowed the project to move to a permanent installation assessing the benefits over a longer period. During the R&D Phase the system demonstrated a high availability with an average of 20% energy reduction and peaks of 40% energy reduction when compared to conventional control. To date the system has reliably demonstrated energy savings and offers the potential to contribute significantly to United Utilities objective to reduce its Carbon emissions by 8% by 2012 if the benefits are replicated across the companies asset base of large ASP’s. Source: WEFTEC 2009 Proceedings
Posted: August 27th, 2010 | Filed under: 50k-100k, Electric, Sanitary Sewer, Stormwater, Waste Water Treatment, Water Treatment | Tags: Cost Savings, Energy Savings, Environmental Impact, Reduced Carbon Footprint | No Comments »
Joint Effort by California Department of Water Resources and California Energy Commission
In 2005, California, led by the California Energy Commission, began a serious look at the waterenergy-greenhouse gas relationship in the state. Saving water saves energy. Saving energy saves water, both where there are cooling towers on buildings and at thermal power plants which use water for cooling. You save more in Southern California than in Northern California because of the energy attached to imported water. Saving water used outdoors is good (pumping, treatment and delivery), saving water used indoors is better (no waste removal, treatment and discharge) and saving hot water is still better (no energy to heat the water too). This paper will build on the work done by the California Energy Commission by presenting information on both sides of the connection: energy for water and water for energy. Source: WEFTEC 2009 Proceedings
Posted: August 27th, 2010 | Filed under: Electric, Waste Water Treatment, Water Treatment | Tags: Energy Savings, Environmental Impact, Plant Sustainability, Reduced Greenhouse Gas Emissions, Smaller Carbon Footprint, Water Conservation | No Comments »