Nothing to fear
Elizabeth Toot–Levy, Frank Foley, Jean Chapman Smith, and Kristina Granlund
Screening assessment helps Ohio utility put the risks of pharmaceuticals and personal care products in perspective
In 2008, newspapers across the United States ran Associated Press (AP) articles on pharmaceuticals in drinking water supplies. The stories prompted a congressional hearing, numerous pharmaceutical-collection events, and at least one state to test its waterways for pharmaceuticals and personal care products (PPCPs).
The articles also prompted the Northeast Ohio Regional Sewer District (NEORSD; Cleveland) to screen the Greater Cleveland area’s aquatic environment for PPCPs. NEORSD examined the prevalence of PPCPs in water and wastewater, and evaluated treatment plants’ removal efficiencies of these substances. While not a true risk assessment, NEORSD’s results can be used to put PPCPs into perspective. Read full article (login required)
Microconstituents: What to expect in your permit
Sarah Reeves and Peter Littlehat
Microconstituents are beginning to make their way into discharge permits in the United States. Removal of microconstituents often requires tertiary treatment, and utilities are interested to know what permit limits they might expect in the future as they plan for capital improvements. The U.S. Environmental Protection Agency (EPA) currently is focusing on developing methods to determine the endocrine-disrupting impact of particular compounds. EPA has developed some criteria for endocrine-disrupting compounds (EDCs), but the states have been slow to turn these criteria into standards, and their inclusion into permits is much slower. While several states are moving forward with developing standards for diazinon, polychlorinated biphenyls (PCBs), nonylphenol, atrazine, and tributyltin, permit holders probably will not see EDCs in permits in the near future. Read full article (login required)
Operations Forum Features
Data? Why do we need that?
Karen M. Morris
Using data to drive collection system maintenance
Operating and maintaining a sewer collection system used to be a fairly simple and straightforward job. A complaint call comes in and a crew responds. If the crew finds something — say, a collapsed pipe — the line is repaired and the problem is resolved. Or if the crew finds roots or grease, the line gets added to a regular cleaning list.
That is, of course, if the field information gets back to the office staff. Oh, and the office staff needs to remember to add that line to the cleaning list. And if/when all of that does happen, everyone involved prays that the list is never lost.
But the days of relying on complaint calls to drive the daily work of the operations and maintenance groups are gone. With so much pressure today from environmental advocates and unfunded federal mandates, as well as a weak economy forcing departments to do more with less, operations and maintenance groups must rethink their processes. A large part of this involves becoming more aware of the data collected, how these data can be better utilized, and the technology tools available to assist with that process. Read full article (login required)
Amanda H. Pollack
Sewer rehab gains postpone expansion plans
Fruitland, Md., is a small city, centrally located on Maryland’s Eastern Shore. Like many cities on the Eastern Shore, the area has generally sandy soils and a high groundwater table and has experienced elevated growth throughout the past few years. However, the increased flows at the wastewater treatment plant seemed to outpace development.
Based on the increasing peak flows following rain events and 30 years of experience, the city’s director of utilities, Joseph Derbyshire, recognized that significant infiltration and inflow (I/I) was entering the sanitary sewer system through leaking brick manholes, cracked pipes, offset joints, and lateral-to-main connections. Fixing this problem kicked off a large undertaking in a small city. Read full article (login required)
Understanding vacuum sewer technology
An alternative collection system
Public works directors take a long view when they make infrastructure decisions. The true cost of a project or technology is determined by many factors over a period of years, often decades. Installation costs, manufacturer support, operations, maintenance, and service are all part of the value equation.
For centuries, gravity has been the usual choice for wastewater conveyance. It is a known system that’s relatively easy to understand. Newer technologies, such as vacuum sewers, are something of an unknown.
Public works officials who have firsthand knowledge of vacuum sewer technology will tell you that installing and maintaining a vacuum sewer system is easy and the service life is measured in decades. The first vacuum sewer was installed in the United States in 1972, and 30-year-old vacuum systems are still functioning well with minimal maintenance.
Vacuum sewers have proven to be an affordable, efficient, reliable technology. Knowing how they function and are maintained will shed light on why many municipalities are turning to vacuum sewers as their preferred conveyance system. Read full article (login required)
Polymer evaluation basics
Designing an impartial and fair qualification test
Coagulant polymers are one of the largest expenses for most wastewater treatment plants, so it is worthwhile to carefully plan the competitive qualification tests for selecting a new polymer to ensure that money is well spent. Unfortunately, the testing is something most plants hate to do and postpone as long as possible. This is due, in part, to the way many choose to evaluate polymers and the lack of any meaningful guidance in the literature.
There is a straightforward way to plan and execute a polymer evaluation. Both the polymer vendor and the plant operator have a role to play. The keys to success are in the design of the test plan. Read full article (login required)