Features

January 2013, Vol. 25, No.1

Grappling with data

Public participation GIS for TMDL compliance

grappling art Brian Bugg and Josh Streufert
Restoring the health of any large body of water requires an extensive collaboration among stakeholders, including state and federal regulators, local municipalities, scientists, and local industry. These stakeholders must collaborate to execute projects designed to improve the watershed’s quality by measuring, tracking, and implementing best management practices to reduce pollutants and suspended solids.
This effort can require years of sampling, testing, and project implementation to reduce contaminants. Sometimes, this involves hundreds of people across thousands of projects, resulting in a tremendous amount of disparate data. Read full article (login required) 

 

MBR retrofit keeps water flowing

Recovery of more water for reuse by retrofitting existing facilities with a membrane bioreactor system is a cost-effective dream coming true for Riverside, Calif.

MBR art Brad Hemken, Gary Valladao, Robert Matthews, and John Corbin
The Southern California city of Riverside has a mission to enhance the quality of life for its residents. One way to achieve this is to offset projected demands for water through the increased use of recycled water for nonpotable needs. To consistently treat wastewater to the stringent water recycling standards established by the California Department of Health Services under Title 22 of the California Code of Regulations, the city requires a reliable treatment system that generates both a high-quality effluent and more recycled water.
The Riverside Regional Water Quality Control Plant (RWQCP) serves nearly 300,000 residents in Riverside and several neighboring communities. A comprehensive master plan, completed in February 2008, spawned expansion plans for the two-part system. Read full article (login required) 

 

Operations Forum Features

CMMS facilitates condition-based maintenance


Saving money for municipal water systems

CMMS art Paul Lachance

While it may be true that the “squeaky wheel gets the grease,” maintenance professionals know that expensive machinery needs grease long before anything starts squeaking.

But timing preventive maintenance tasks can be tricky. Waiting to make repairs only after equipment breaks exacts a high toll on budgets and productivity. By the same token, jumping the gun on maintenance also can be costly if parts get replaced before the end of their run.

To reach a happy medium, industries, municipalities, and even the Pentagon are turning to condition-based maintenance (CBM), a system incorporating real-time data into assessments about the health of equipment, helps schedule maintenance work can be done when it is actually necessary — not according to a rigid schedule. Read full article (login required) 

 

Automating control for diurnal loadings

Pilot test shows that real-time control of solids retention time improved instantaneous SRT and F:M control at the Sacramento Regional Wastewater Treatment Plant

diurnal art Jeremy Boyce and Joshua Nurmi
Daily flow and loading fluctuate continuously at the Sacramento (Calif.) Regional Wastewater Treatment Plant (SRWTP). These fluctuations exacerbate nocardioform blooms in the secondary process and can adversely affect effluent quality. A study team tested the best available instrumentation — on-line, total suspended solids (TSS) analyzers and solids retention time (SRT) control software — to automate activated sludge flow in real time. The team hoped these tools would enable operators to provide a more consistent SRT and food-to-microorganism ratio (F:M) than found in typical diurnal loadings. Read full article (login required) 

 

Performing under pressure

Pilot-testing a tertiary ultrafiltration membrane system at significant pressures reduced coliform concentrations and achieved ultralow phosphorus levels

pressure art LeAnna Risso, Douglas D. Drury, and Bill Shepherd

In 2008, the Clark County (Nev.) Water Reclamation District (CCWRD; Las Vegas) decided to replace its failing tertiary sand filters with tertiary membrane filtration and exchange its ultraviolet disinfection system for ozone disinfection.

Ultimately, CCWRD concluded that its application of membrane technology as a tertiary filtration process resembled a drinking water application more closely than a membrane bioreactor (MBR) system. Based on this finding, CCWRD significantly increased the pressure used to test membrane integrity, and operations staff worked with a field service technician from the membrane vendor to repair the membrane fibers. Following these changes, the performance of the pilot system improved dramatically. Read full article (login required)