Features

May 2009, Vol. 21, No.5

Stormwater Management: The Next Frontier

After languishing for decades in relative obscurity behind its drinking water and wastewater counterparts, stormwater management is assuming greater importance for many municipalities and utilities

stormwatermgmt.jpg Jay Landers

Despite its increasing prominence, the field of stormwater management must overcome numerous hurdles, such as lack of awareness by the public, inadequate funding, and organizational and regulatory challenges, for it to improve water quality in the face of increased development.

Among the many challenges facing stormwater managers, one of the most critical involves educating the public to understand that stormwater is an asset and not a liability. “We’re a long ways away” from this goal, said Daniel Medina, global technology leader for watershed services at CH2M Hill (Englewood, Colo.), largely because stormwater remains invisible to most people unless a problem such as flooding occurs.   Read full article (login required)  

 

 Forecast Calls for High-Tech Water Management Tools

 South Florida agency receiving near real-time rainfall animation using Google Earth

forecastcalls.jpg Chandra Pathak, Anand Trivedi, Ryan Boyce, and Dale Lutz
When many people hear “Google Earth,” they think of the remarkable aerial images they can find online of their home and street. But to the officials at the South Florida Water Management District, Google Earth will soon mean things even more remarkable, including better flood control during the wet season and more efficient water conservation during the dry one.

Thanks to a first-of-its-kind application of Google Earth, the district soon will be receiving nearly real-time animation of the precipitation throughout its 46,440-km² (17,930-mi²) area — information it can use to better manage the district’s unique hydrology.   Read full article (login required)  

 

 Holistic Approach

 Renewable energy options should not address global warming at the expense of food and water resources

holisticappr.jpg Mark E. Capron

Reducing carbon dioxide emissions is an enormous task — so enormous that we need to stop using fossil fuels and temporarily sequester carbon just to reduce emissions, let alone eliminate them or reverse the damage. Growing biofuels to replace fossil-based fuels is problematic. Both   biofuel and food crops require sunlight, water, nutrients, and carbon dioxide. We already have tapped out 30% of Earth’s surface and the 1% of water that is fresh, but not frozen, to meet our food and water needs. We cannot afford to ignore or damage the remaining 70% of Earth’s surface and 97% of its water.

However, there is another possibility. The oceans have more than twice the sunlit surface area of land, and 100 times the (unfrozen) water. Although ocean surfaces generally lack nutrients, they also have dead zones caused by excess nutrients. In addition, oceans absorb carbon dioxide, which is making them acidic. An ocean-based biofuel system might replace fossil-based fuels without shrinking food and water supplies.   Read full article (login required) 

 

Operations Forum Features

Raising the Bar

Trickling filter upgrades provide better performance and stormwater storage

raising.jpg Scott Dunn

In 2004, the Bethel Park (Pa.) Municipal Authority was facing several challenges at its 4.92-mgd (18,600-m³/d) wastewater treatment plant (WWTP). Biochemical oxygen demand and ammonia levels in the effluent were above compliance limits, and the plant’s influent equalization tank overflowed into the plant’s receiving stream during severe storms. A full optimization study pinpointed what was happening, and the  authority found an uplifting solution to both its process and stormwater problems: elevated trickling filters.

The upgrade project replaced the trickling filter media, which solved the compliance problems, and also elevated the media about 7.5 ft (2.3 m), which provides about 800,000 gal (3 million L) of storage under each unit.   Read full article (login required)  

 

Skimming the Surface

 Options for solids and floatables control

skimming.jpg Curtis D. Courter, Seth Bradley, and Brandon C. Vatter

As the Sanitation District No. 1 of Northern Kentucky (SD1) began investigating ways to control solids and floatables (S&F) from exiting combined sewer overflows, it developed a plan to consider the effectiveness and   operations and maintenance (O&M) requirements for a range of simple options.

Each option was assesses with an eye toward design considerations, effectiveness, cost, and operations and maintenance to develop. SD1 then pilot-tested potentially cost-effective and efficient options.

This article summarizes SD1’s review of simple S&F controls and the results of its pilot program to provide snapshots of several available technologies.   Read full article and online supplement (login required)  


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