ABSTRACT The City of Richmond has a population of approximately 180,000 and is located on a flood plain at approximately sea level. These physical attributes present numerous challenges with underground utility design, including sanitary sewers.
On January 21, 2005 the City declared a local state of emergency near the intersection of No. 3 Road at Cook Road due to the development of a large sinkhole (10 x 8 x 1.5 metres deep). A commercial building had partially collapsed and the City’s sanitary gravity main located at a depth of 4.5 metres, at an extreme flat grade of 0.27% and 2.0 metres off the face of a 100 metre long building, was no longer functional. City staff employed a unique methodology to return the sewer main to service and installed a City invented manhole pump/SCADA/bypass system to allow continuous sanitary service. All options to restore the collapsed sewer were exhausted starting with the seemingly least expensive methodology to repair the sewer at the collapse point leading to the adopted solution of re-routing the main. Construction of the re-routed main required a 5-metre deep excavation immediately adjacent to a 32-year old commercial building with substandard footings bearing on soft soils. With the ground water table at a depth of approximately 1.0 metre, uncontrolled dewatering would result in considerable building structural damage. Dewatering was further complicated by tidal fluctuations of the groundwater table. A grout curtain which is new technology not previously used by the City was constructed, leading to successful project completion.
BACKGROUND The City of Richmond is part of the Greater Vancouver Regional District in British Columbia, Canada and has a population of approximately 180,000 in a region of overall population of approximately 2.2 million. The City is located on a flood plain with elevations ranging from approximately 0.6 metres to 2.5 metres above sea level. These physical attributes present numerous challenges and opportunities with underground utility design and construction. Design and construction of gravity sewers provides particular challenges given the consistent grades required between manholes and the considerable depths required to provide pipe slopes that achieve the required hydraulic capacities.
Past practice sanitary sewer design dictated that sewers be constructed within right-of-ways at the rear of properties or through right-of-ways secured from property owners. The philosophy of the time was to minimize potential utility conflicts due to congestion, to maximize separation from the potable water main system, to connect to existing septic fields and to minimize construction restoration costs. Accordingly, approximately 500 kilometres of sanitary sewer mainlines were installed in this manner over several years.
On January 21, 2005 the City of Richmond Mayor declared a local state of emergency near the intersection of No. 3 Road and Cook Road in the City Centre area. A considerable sinkhole with dimensions approximately 10 metres long x 8 metres wide x 1.5 metres deep developed adjacent to a strip of commercial buildings.
Incidental to the sinkhole was the partial collapse of a commercial building and damage to the City’s sanitary gravity main located at a depth of 4.5 metres (Photo1). This 200 mm diameter sewer design, following the design philosophy of the time, was at a very flat grade of 0.27%. Shortly after this sewer was built 45 years ago, an approximately 100 metre long strip of commercial building was constructed 2.0 metres from the sewer centerline. The sewer was located in a narrow 6.0 metre right-of-way and was near the end of the system that serves one of the more densely populated areas of the City and accordingly, carried considerable flow.
Getting the PCBs out
Who: Jersey City, N.J., Municipal Utilities Authority Tons of clean sediment removed: 4,469 Tons of PCB-contaminated sediment: 2,502 Consulting engineer: Boswell Engineering: South Hackensack, N.J. Environmental maintenance contractor: National Water Main Cleaning Co.; Newark, N.J. Subcontractor: Montana Construction Co.; Lodi, N.J. Pump operation: Sunbelt Rentals Inc.; Maple Shade, N.J. Total project cost: $5.29 million Contaminant remediation: $1,446,564 Funding: $3,843,653 in low-intere...
The call came from a Kennedy township homeowner that the smell of raw sewage was in the air and they were tired of the smell. Dave Gasparovich went out and started walking the very hilly area (15% grade or more) in search of the culprit. What he found was incredible, incredibly bad. The 12 manholes he discovered in the woods had been installed in the late 70’s and were connected with clay pipe. The smell was coming from these structures, some of which that had been almost totally destroyed by Hydrogen Sulfide...
ABSTRACT
County Sanitation District 1 (CSD-1) provides wastewater collection services to about 269,000 connections in the Sacramento, California region. CSD-1 has nearly 2,800 miles of mainlines and collectors and operates 95 sewer pump stations. CSD-1 has implemented a risk based asset management program in both the pipeline and pump stations areas of the collection system. Though the two strategies are significantly different, they are both based on the common idea ofincorporating dollar-based risk into...
The River Oaks subdivision is an affluent, mature residential community located in Fairfax, County Virginia which includes 114 existing single family dwelling units with individual septic tank drainfields. The Fairfax County Health Department determined that several drainfields have failed and expressed concern that others would soon fail. In order to prevent the health and environmental problems associated with failing drainfields, a wastewater collection system was needed to convey wastewater to the nearby...
With the aid of InfoWorks CS, the Springfield Water and Sewer Commission (SWSC) has been able to find a cost-effective and environmentally-sustainable alternative to a proposed CSO relief project.
Springfield is in south-western Massachusetts, New England, and is the area’s major urban center and largest community. The Connecticut River, one of the state’s key waterways, forms its western border. To the north of the city is the Chicopee River, a tributary to the Connecticut, and another small tributary, the Mill...
ABSTRACTLouisville and Jefferson County Metropolitan Sewer District (MSD) is responsible for stormwater and wastewater service for the Louisville, Kentucky metropolitan area. A longstanding problem for MSD has been basement flooding due to sewers that are surcharged from wet weather.
A non-traditional program was developed by MSD as a means to address this problem in a cost effective and timely manner. The Plumbing Modification Program began in 1993 as part of the combined sewer overflow program. The program...
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The problem
Most wastewater companies face an ongoing problem of meeting the demand for maintaining and replacing their pipes and sewers as required. The press frequently carries stories on the very high cost of this backlog, and exhorts companies to make inroads into infrastructure improvements.
Companies approach the backlog by looking at the most pressing problems with the best cost/benefit returns, because that is generally all they can afford to work on in terms of both...
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The perennial sewage problem in Chitungwiza, a satellite town of Harare, has reached alarming levels as 500million liters of raw human sewage have found their way into Manyame dam, which supplies water to the capital city.
The country and virtually all its institutions have virtually gone down because of the economic and social turmoil precipitated by the Robert Mugabe led government's decision to seize mostly white owned commercial farms.
The town's treasury has no...
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One of the key words being used in the water and wastewater industry globally is ‘risk' . Asset managers now plan the most cost-effective approaches to managing their network by determining the risk grade for each asset.
Risk is the product of two factors – the impact of failure, multiplied by the probability of failure. However, measuring these two factors is a time-consuming process if approached manually, and utilities rarely have the level of engineerin...
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This is the first in a series of articles about InfoNet, Wallingford Software's purpose-built network information system for water and wastewater network infrastructure. The articles will describe how InfoNet addresses and solves many of the issues of the storage and use of asset data in water companies all around the world.
This first article focuses on a problem that most water and wastewater engineers face most days – finding and retrieving, easily and quickly, every...
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Why is flow metering important?
There are two fundamental reasons for the importance of flow metering and measurement. First, information, either for direct management needs - “You can't manage what you can't measure” - or indirectly for further analysis, including modeling. The second is its role in operational control. SCADA measurement for example is often directly linked to system controls, tracking trends and changes in system characteristics, just like a blood...
Eliminating sediment and debris from municipal water mains that deliver potable water to residences and businesses can help preserve water quality, increase flow and pressure - and maintain a municipality`s good reputation.
The Sleeper open pit gold mine operated from the mid-1980s through the mid-1990s. Operations were mostly sub-water table and extensive dewatering was required to lower groundwater levels by 180 m. Dewatering flows peaked at 930 L/s, with most flow contributed from an alluvial aquifer. After completion of mining, the pit was rapidly filled with water pumped from the alluvial aquifer to reduce the exposure time of sulfide wall rocks and waste rocks in the ultimate pit. The pumped alluvial groundwater provided a...
Pollution in water
supplies has always been a concern for water companies and with today’s political
climate the issue has never been more important. The threat of terrorism and the
requirements of Homeland Security and similar initiatives around the world require
that water companies maintain detailed plans for how to react swiftly in the event
of a pollution incident, whether accidental or malicious, and that they are ready
to implement the plans effectively.
Although many of
the counter-m...
Introduction
The flow variations in sewers have been modelled for several years with a comparatively high degree of accuracy as far as the diurnal variations and responses to climatic conditions are concerned. However, until comparatively recently the variations in flow due to fluctuations in groundwater levels, soil storage capacity and wetness of the catchment have only been modelled in basic terms. For the past decade it has been possible to use runoff models that respond to the increasing wetness of the...
Not everyone in the Water Industry is convinced about the benefits of Network Modelling, believing that the investment required cannot be justified. Dan Stevens, Senior Support Engineer for Water Supply Software at Wallingford Software discusses the Business Case for Network Model based System Management, dispelling some of the myths surrounding this subject.
Some of the common misconceptions surrounding Network Modelling are:
You need boffins to set up and run the models
Once completed the models soon...
Paul Banfield, Sales Director of Wallingford Software, argues that, for the first time in the history of hydraulic modelling, modellers can now reap the elusive benefits of larger hydraulic models, in turn enhancing the quality of operational and investment decision-making.
Introduction
A desire for increased accuracy, simplicity and completeness is the primary reason why modellers wish to build large hydraulic models:
To reflect the network as closely as possible
To incorporate all the available data...
THE TERM, “decentralized waste-water management,” refers to the process of treating and discharging treated wastewater in the local vicinity where it is generated. Decentralized systems typically use the soil as the final receptor of the treated wastewater instead of discharging to surface waters, which are generally the receptors of treated wastewater from larger centralized treatment plants. Wastewater is further treated in the soil; some is utilized by plants and, in many environments, much of it will recharge...
As researchers analyze the soils’ ability to absorb discharge, more knowledge is gained about alternatives to septic tanks and standard drain fields that include peat filter systems, constructed wetlands and drip irrigation.
ONE out of every four American households currently treat and release wastewater on their own property. Although most people assume that on-site systems are confined to rural areas, in fact half are in suburbs and a few even remain within the confines of large cities.
Public works engineers...
Company Overview
The LURA d.d., founded in August 1999 by merger of the Lura Group member companies, is the leading dairy company in Croatia. It consists of the following factories: Factory Zagreb, Factory Bjelovar and Factory Zadar.
In period 1993 – 1999 LURA d.d. existed as LURA Group d.o.o. which consisted of Dukat d.d. (Factory Zagreb), Sirela d.d. (Factory Bjelovar) and Mljekara Zadar d.d. (Factory Zadar) in the form of the joint stock companies.
The company’s success and growth is based on top quality...
When World Color Press, Dyersburg, TN, decided to replace its outdated computerized supervisory control system for its large solvent recovery operation, it turned to AMCEC Inc., Lisle, IL. World Color Press wanted a system that would provide uncomplicated screens and flexible graphic importing. It also wanted to avoid long hours of training.
A solution was found in an object-based automation software called Lookout, from National Instruments Corp., Austin, TX. The PC-based human-machine interface (HMI) supervisory...
Bell Canada provides a comprehensive environmental training program, known within the company as the Internal Environmental Evaluation (IEE) training program, to it’s employees. The program addresses all of the major environmental programs and policies within Bell which include:
Hazardous Material Management,
Non-Hazardous Material Management,
Zero Waste/Municipal Recycling,
PCBs,
Environmental Permitting,
Spills Management,
Wood Pole Recycling and,
Management of Manhole/Access Chamber Effluent....
INTRODUCTION
The condition of public infrastructure has become a common story in the United States media. Numerous newspaper, magazine, and television reports have described the need to upgrade the nation’s aging infrastructure. Estimated costs for these upgrades are staggering, typically in the hundreds of billions if not trillions of dollars. Despite these high estimates, there is no unified funding mechanism in place to finance these needed improvements. Thus, utilities must develop effective and rational...
`The oceans are in trouble and so are we,` oceanographer Sylvia Earle, National Geographic explorer in residence and researcher for the Smithsonian, was quoted as saying in an article on the web by Seth Borenstein writing for the Philadelphia Inquirer and San Jose Mercury News Washington Bureaus. Citing a study by the Harvard Medical School`s Center for Health and the Global Environment covering 1976 to 1996, Borenstein reports a greater than fourfold increase in harmful algal blooms (74 to 329). `stranding of...
A position paper prepared by the Soil & Groundwater Technology Association (SAGTA), for the Department of the Environment, Transport and the Regions (DETR) and the Environment Agency (EA) in November 1998. It sets out an industry view on the knowledge gaps and research needs for the risk based management of contaminated land for the workshop ‘Matching Contaminated Land Research to Need’ planned for April 1999. SAGTA member organisations are drawn from leading members of UK industry. They are actively addressing...
Unlike organic contaminants (and similar to metals), radionuclides cannot be destroyed or degraded; therefore, remediation technologies applicable to radionuclides involve separation, concentration/volume reduction, and/or immobilization. The most commonly used treatment technology for radionuclides in soil, sediment, and sludge is solidification/stabilization (S/S). This treatment technology is described briefly below.
Solidification processes produce monolithic blocks of waste with high structural integrity....
On 12th March 1997, the European Commission adopted a proposal from the Environment Commissioner Ritt Bjerregaard on a European Union strategy to combat acidification. The strategy will, by 2010, reduce significantly the extent of the areas in the European Union where the tolerance of sensitive ecosystems to acidity is exceeded. Main elements of the strategy include establishment of national emission ceilings for each acid rain pollutant; ratification of the UN protocol on further reductions of sulphur emissions;...
It may be necessary to know other subsurface information to remediate nonhalogenated semivolatile organics in water. Treatability studies may be required to determine the contaminant biodegradability for any biodegradation technologies. Treatability studies are also necessary to ensure that the contaminated ground water can be treated effectively at the design flow. A subsurface geologic characterization would be particularly useful to any isolation or stabilization technologies. Ground water models are also...
It may be necessary to know other subsurface information to remediate inorganics in ground water, surface water, and leachate. Treatability studies are usually necessary to ensure that the contaminated ground water can be treated effectively at the design flow. A subsurface geologic characterization would be particularly important to characterize the effects of adsorption and other processes of attenuation. Ground water models are also often needed to predict flow characteristics, changes in contaminant mixes and...
Introduction
Fracturing is an enhancement technology designed to increase the efficiency of other in situ technologies in difficult soil conditions. The fracturing extends and enlarges existing fissures and introduces new fractures, primarily in the horizontal direction. When fracturing has been completed, the formation is then subjected to vapor extraction, either by applying a vacuum to all wells or by extracting from selected wells, while other wells are capped or used for passive air inlet or forced air...
ABSTRACT
Bioslurping involves the simultaneous application of vacuum enhanced extraction/recovery, vapor extraction, and bioventing to address LNAPL contamination. Vacuum extraction/recovery is used to remove free product along with some groundwater, vapor extrac tion is used to remove high volatility vapors from the vadose zone, and bioventing is used to enhance aerobic biodegradation in the vadose zone and capillary fringe.
The bioslurping system is made up of a well into which an adjustable length `slurp...
Abstract
As water and sewer costs are expected to increase over the next decade, membrane technology will continue to be a viable and economical option in the recovery and reuse of water. This paper describes the mechanism of membrane effected separation (specifically reverse osmosis, ultrafiltration and microfiltration), membranes commercially available, membrane element configurations, and how complete membrane systems are designed. The paper also discusses case histories of a variety of proven applications,...
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Summary:
The adjacent cities of Tempe and Mesa, Arizona, rely on a combined wastewater collection system comprising 434 miles of sanitary sewer lines and more than 6,000 manholes. The 40-mgd system serves a total metropolitan population of nearly 450,000. Turbulent flows at the force main discharges and other areas of the sewer system cause considerable hydrogen sulfide off-gassing and resultant
odor emissions through nearby manhole covers. In addition, low sewage volume,...
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