摘要:

The distribution system for the City of Westerville, Ohio, includes two pressure districts and three elevated water tanks. The first district includes two water storage tanks. Otterbein tank, the system's original tank, holds only 300,000 gal. Pointview tank, constructed later to meet increased system demand, holds a significantly higher volume of water—1.5 million gallons. The hydraulic gradient of the overflow on the Otterbein tank is 9 feet lower than the overflow of Pointview tank. Pointview was designed with an elevation difference to increase distribution system supply and pressure. The Otterbein tank uses an altitude valve to shut off the flow of water to the tank as it reaches overflow level. When distribution system pressure drops, the altitude valve opens and lets water out of the Otterbein tank. In order to drop distribution system pressure, we had to lower the Pointview tank considerably and shut off the plant's high‐service pumps. When demand peaked during the summer, it was not prudent to lower the tank level for fear of a resulting shortage of finished water. At the same time, there was concern about the Otterbein tank water becoming stagnant. One option was to take the tank completely out of service. However, we ruled this out because we wanted to maintain as much elevated storage of potable water as possible. The Westerville Water Plant Mechanical Department constructed a system that pumps water out of the Otterbein tank while allowing the altitude valve to continue working normally. The new system, which still employs an altitude valve to fill the tank, uses a pumps to lower the tank level.

ISSN:0149-8029    

DOI:10.1002/j.1551-8701.1995.tb01267.x

出版商:Wiley    

年代:1995

数据来源: WILEY

摘要:

Do you like people and genuinely care about the health and welfare of your co‐workers? Are you organized? Do you have a working knowledge of your utility? If you answered “yes” to these questions, then you are an excellent candidate for a career in safety. Safety professionals will be in demand for the remainder of the 1990s. Lowering injury and medical costs to the utility and protecting a reduced workforce will become paramount concerns. If you have never considered a career in safety, maybe it's time.

ISSN:0149-8029    

DOI:10.1002/j.1551-8701.1995.tb01268.x

出版商:Wiley    

年代:1995

数据来源: WILEY

摘要:

This month's question asks about compliance with the Disinfectant/Disinfection Byproduct (D/DBP) Rule, the deadline for compliance, and whether the regulation makes provision for the haloacetic (bromochloroacetic) acid. The answer first addresses the compliance question, citing the Stage 1 proposed D/DBP Rule maximum contaminant levels (MCLs) for total trihalomethanes (TTHMs) and for the total five haloacetic acids (HAA5). The article gives the time period required in which to comply after promulgation of the rule. Specific instruction regarding bromochloroacetic acid is given.

ISSN:0149-8029    

DOI:10.1002/j.1551-8701.1995.tb01269.x

出版商:Wiley    

年代:1995

数据来源: WILEY

摘要:

Cryptosporidium and the threat of cryptosporidiosis have emerged since 1976 when it was learned that this organism could cause disease in humans. New attention is being focused on determining and reducing the risk for cryptosporidiosis from drinking water. Answers to frequently asked questions are provided in this article.

ISSN:0149-8029    

DOI:10.1002/j.1551-8701.1995.tb01270.x

出版商:Wiley    

年代:1995

数据来源: WILEY

摘要:

In the past, we measured the filter freeboard (the measurement from the top of the filter media to the top of the washwater trough) quarterly. To accomplish this task, we had to first drain the filter, then, standing on top of the washwater troughs, measure at various places to get an average. This practice was obviously hazardous because someone had to straddle the washwater troughs and enter a confined space to take the measurements. Adding to our difficulties, we did not have a good way to measure filter bed expansion during a filter backwash. We constructed a gadget to perform this task in a safer, more efficient manner. A list of materials and construction information is provided.

ISSN:0149-8029    

DOI:10.1002/j.1551-8701.1995.tb01271.x

出版商:Wiley    

年代:1995

数据来源: WILEY

摘要:

There is nothing more refreshing after a long, exhausting excavation than a cold blast of water to the face—especially in the winter. This gadget—the leak spray suppressor—stores easily behind a truck seat and stops these unwelcome showers. The suppressor makes more manageable the job of excavating a main that cannot be shut down completely. The suppressor effectively controls the spray so that the excavation to the sides and under the main can be completed. A list of materials and construction information is included.

ISSN:0149-8029    

DOI:10.1002/j.1551-8701.1995.tb01272.x

出版商:Wiley    

年代:1995

数据来源: WILEY