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Raleigh, NC, United States

Siemers-Kennedy L.C.,GHD Inc.
Pipelines 2015: Recent Advances in Underground Pipeline Engineering and Construction - Proceedings of the Pipelines 2015 Conference

An extended period calibration was performed for Sydney Water Corporation in Australia, a regional utility which serves 4.6 million people and manages 13,000 miles of water mains. The purpose of the project was to calibrate existing models to maintain an accurate representation of the water distribution system, customer demand patterns, and controls. The calibrated models would then be able to be used by the utility for many purposes including future growth planning, operations optimization, water quality modeling, and incident management. The calibration process consisted of updating models based on the most recent geospatial data of the network assets, updating the demands from the customer usage database, and updating the controls from the SCADA system. The calibration tolerance of +/-1 m difference between observed and measured hydraulic grade over a 24-hour period was achieved for the majority of calibration points. In order to achieve calibration, the boundary conditions and initial settings were updated based on measured data, the control settings were updated, and the demands were updated to match the demand patterns observed on the calibration day. In some cases additional modifications were needed to achieve the calibration tolerance, such as: pump curve adjustment, valve diameter adjustment, pipe roughness coefficient adjustment, and valve operational status. Identifying these operational issues as a result of the calibration process provided a benefit to the utility and allowed them to focus field efforts on particular areas, such as underperforming pumps and water mains with potential closed valves or other restrictions. © 2015 ASCE. Source

Grabow G.L.,North Carolina State University | Ghali I.E.,North Carolina State University | Huffman R.L.,North Carolina State University | Miller G.L.,North Carolina State University | And 2 more authors.
Journal of Irrigation and Drainage Engineering

Increasing competition for water and the desire for high-quality turfgrass require sound irrigation water management. The main objective of this study was to evaluate two types of commercially available irrigation control technologies: one based on evapotranspiration (ET) estimates and the other based on feedback from a soil-moisture sensor (SMS). Irrigation treatments were combinations of controller technology: a timer-based standard controller system (TIM), an add-on (1 set point) SMS system (SMS1), and an evapotranspiration (ET)- based system (ETB), and watering frequency: weekly, twice per week, and daily (1, 2, and 7 days per week, respectively) plus a 10th treatment of an on-demand (2 set point) SMS system (SMS2). Both irrigation efficiency and adequacy were best for the SMS2 treatment when averaged over all three years. The SMS1 treatment provided good irrigation efficiency, but irrigation adequacy suffered, most noticeably with the twice per week treatment. The ET treatment provided good irrigation adequacy, but had the poorest irrigation efficiency. SMS treatments resulted in average water savings of 39% in SMS1 treatments and 24% in the SMS2 treatment compared to the timer-based treatments, whereas the ET treatments applied 11% more water, on average, than the timer-based treatments. The weekly SMS1treatment applied the least amount of water (10 mmweek-1), whereas the twice per week ET treatment applied the most water (26 mmweek-1). © 2013 American Society of Civil Engineers. Source

McGovern T.,Hampton Roads Sanitation District | Sullivan B.,GHD Inc.
AWWA/WEF Utility Management Conference 2013

Implementing, sustaining, and improving a Computerized Maintenance Management System (CMMS) or an Enterprise Asset Management System (EAMS) is a continual process that requires many factors to achieve excellent results and benefits. This continuous process can be similar to a long journey that involves significant advanced planning and the ability to make adjustments along the way. Throughout this presentation, specific steps will be highlighted that were taken by the Hampton Roads Sanitation District (HRSD) during this journey to keep their CMMS evolving to meet their changing needs. The results HRSD has achieved along the way in the journey towards CMMS excellence will also be discussed. © 2013 American Water Works Association. Source

Syachrani S.,Oklahoma State University | Jeong H.S.,Oklahoma State University | Chung C.S.,GHD Inc.
Journal of Pipeline Systems Engineering and Practice

One of the key components in successfully implementing asset-management programs is to have accurate and reliable deterioration models for the assets because the deterioration models are the core computational basis for predicting and prioritizing future maintenance, rehabilitation, or replacement activities of the assets. Many large and advanced utilities have put extensive efforts into collecting condition assessment data of their assets since the late 1990s. This change has posed new challenges in developing deterioration models. This paper presents a framework for developing dynamic deterioration models that can avoid the uniform treatment of the entire sewer pipe network by using the clustering and filtering process on the basis of location-related attributes and operational conditions. The dynamic deterioration models are dynamic because they are dual models for a single sewer network; one model is for individual prediction and the other for group prediction. The performance and benefits of the dynamic deterioration models are discussed with the conventional deterioration models developed in this study for comparison purposes. More realistic and reliable decisions can be made by using the dynamic deterioration models, which can translate into accountable short-term and long-term funding strategies for sustainable infrastructure asset management. © 2011 American Society of Civil Engineers. Source

GHD Inc. | Date: 2008-06-12

Filtering units for wastewater; Industrial-water purifying apparatus; Ozone sanitizers for air and water; Waste water purification units; Water filtering apparatus; Water filtering devices, namely, water purification installations for waste water and sewage consisting of curtains and textile fabrics; Water purification and filtration apparatus; Water purification installations; Water purification units; Water purifiers; Water purifying apparatus; Water purifying units, for potable water for industrial use; Water sterilizers; Water treatment equipment, namely, chemical sterilization units; Water treatment equipment, namely, reverse osmosis filtration units; Water treatment equipment, namely, ultraviolet sterilization units.

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