Corrigendum to: Prioritising fuels reduction for water supply protection

2020 ◽  
Vol 29 (11) ◽  
pp. 1054
Author(s):  
Benjamin M. Gannon ◽  
Yu Wei ◽  
Lee H. MacDonald ◽  
Stephanie K. Kampf ◽  
Kelly W. Jones ◽  
...  

Concerns over wildfire impacts to water supplies have motivated efforts to mitigate risk by reducing forest fuels. Methods to assess fuel treatment effects and prioritise their placement are needed to guide risk mitigation efforts. We present a fuel treatment optimisation model to minimise risk to multiple water supplies based on constraints for treatment feasibility and cost. Risk is quantified as the expected sediment impact costs to water supplies by combining measures of fire likelihood and behaviour, erosion, sediment transport and water supply vulnerability. We demonstrate the model's utility for prioritising fuel treatments in two large watersheds in Colorado, USA, that are critical for municipal water supply. Our results indicate that wildfire risk to water supplies can be substantially reduced by treating a small portion of the watersheds that have dense, fire-prone forests on steep slopes that drain to water supply infrastructure. Our results also show that the cost of fuel treatments outweighs the expected cost savings from reduced sediment inputs owing to the low probability of fuel treatments encountering wildfire and the high cost of thinning forests. This highlights the need to expand use of more cost-effective treatments, like prescribed fire, and to identify fuel treatment projects that benefit multiple resources.

2019 ◽  
Vol 28 (10) ◽  
pp. 785 ◽  
Author(s):  
Benjamin M. Gannon ◽  
Yu Wei ◽  
Lee H. MacDonald ◽  
Stephanie K. Kampf ◽  
Kelly W. Jones ◽  
...  

Concerns over wildfire impacts to water supplies have motivated efforts to mitigate risk by reducing forest fuels. Methods to assess fuel treatment effects and prioritise their placement are needed to guide risk mitigation efforts. We present a fuel treatment optimisation model to minimise risk to multiple water supplies based on constraints for treatment feasibility and cost. Risk is quantified as the expected sediment impact costs to water supplies by combining measures of fire likelihood and behaviour, erosion, sediment transport and water supply vulnerability. We demonstrate the model’s utility for prioritising fuel treatments in two large watersheds in Colorado, USA, that are critical for municipal water supply. Our results indicate that wildfire risk to water supplies can be substantially reduced by treating a small portion of the watersheds that have dense, fire-prone forests on steep slopes that drain to water supply infrastructure. Our results also show that the cost of fuel treatments outweighs the expected cost savings from reduced sediment inputs owing to the low probability of fuel treatments encountering wildfire and the high cost of thinning forests. This highlights the need to expand use of more cost-effective treatments, like prescribed fire, and to identify fuel treatment projects that benefit multiple resources.


2021 ◽  
Author(s):  
Mohamad Anas Abdul Razak ◽  
Ahmad Zawawi Abdul Rajab ◽  
Jay Sern Chew ◽  
John Brian Chesson ◽  
Susin Lim

Abstract Malaysia's government recognizes the high risk that aging idle wells pose to its health, safety and environment and has developed some of the most stringent plug and abandonment, P&A, regulations to protect its future. Corroded casing strings and sustained casing pressure are common issues on its multi-decade old platforms and a risk-based design philosophy has been adopted to balance risk mitigation and operational costs, while still ensuring an eternal barrier. Both conventional rigs as well as rigless hydraulic workover units, HWU, are being used for P&A operations. This study considers the barrier element rationale applied in four offshore wells that were plug and abandoned by cap-rock restoration Perforate, Wash, Cement, PWC, barrier plugs. It also considers the operating window of a jet-based PWC technology to understand the challenges and opportunities for further optimization during HWU operations. Cap rock restoration utilizing both cup-based and jet-based PWC technology is being widely applied throughout Malaysia as a cost-effective alternative to casing section milled barrier plugs. Malaysia's P&A regulation allows isolation at the cap rock level, whereby "Contractor shall adhere to the Cap-Rock Abandonment Applicability Flowchart to identify technically and commercially acceptable candidates for this well abandonment method." The PWC method enables cap rock restoration in a single trip process; whereby the casing annulus is accessed by TCP guns to allow for annular debris to be effectively washed prior to cement plug placement. The process is not limited only to TCP guns; as a mechanical casing perforator was utilized in a shallow cased hole section of one of the wells to avoid damaging the outer casing. A custom BHA was developed and tested to match the cuts from the mechanical perforator. Specially oriented, rotating, wash jets were configured to maximize the annular access during the washing process. The washing effectiveness of this new BHA was confirmed by the massive amount of annular debris that was observed over the surface shakers. Operations were conducted offshore with a HWU with limited infrastructure and operating capability compared to a conventional rig. A PWC candidate screening matrix was applied early during the planning phase to manage rig limitation, well condition and operational risk to ensure successful barrier placement. All cap rock barriers were successfully installed and tested, and no sustained annular pressure remained in any of the wells. Fewer PWC plugs were required than originally planned, due to strict adherence to the Caprock Restoration Plan Decision Tree, resulting in significant cost savings for the project. The detailed time breakdown of the HWU operations provides useful insight into the operational efficiencies and unplanned events during the HWU campaign and lessons learned are shared from the project.


2020 ◽  
Vol 29 (1) ◽  
pp. 42
Author(s):  
Jason Kreitler ◽  
Matthew P. Thompson ◽  
Nicole M. Vaillant ◽  
Todd J. Hawbaker

Modelling the spatial prioritisation of fuel treatments and their net effect on values at risk is an important area for applied work as economic damages from wildfire continue to grow. We model and demonstrate a cost-effective fuel treatment planning algorithm using two ecosystem services as benefits for which fuel treatments are prioritised. We create a surface of expected fuel treatment costs to incorporate the heterogeneity in factors affecting the revenue and costs of fuel treatments, and then prioritise treatments based on a cost-effectiveness ratio to maximise the averted loss of ecosystem services from fire. We compare treatment scenarios that employ cost-effectiveness with those that do not, and use common tools and models in a case study of the Sisters Ranger District on the Deschutes National Forest in central Oregon, USA. Using cost-effectiveness not only increases the expected averted losses from fuel treatments, but it also allows a larger area to be treated for the same cost, simply by incorporating costs and cost-effectiveness into the prioritisation routine. These results have considerable implications for policymakers and land managers trying to minimise risk. Incorporating costs into the spatial planning of treatments could allow more effective outcomes without increasing fuel treatment budgets.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 507-515 ◽  
Author(s):  
David Skuse ◽  
Mark Windebank ◽  
Tafadzwa Motsi ◽  
Guillaume Tellier

When pulp and minerals are co-processed in aqueous suspension, the mineral acts as a grinding aid, facilitating the cost-effective production of fibrils. Furthermore, this processing allows the utilization of robust industrial milling equipment. There are 40000 dry metric tons of mineral/microfbrillated (MFC) cellulose composite production capacity in operation across three continents. These mineral/MFC products have been cleared by the FDA for use as a dry and wet strength agent in coated and uncoated food contact paper and paperboard applications. We have previously reported that use of these mineral/MFC composite materials in fiber-based applications allows generally improved wet and dry mechanical properties with concomitant opportunities for cost savings, property improvements, or grade developments and that the materials can be prepared using a range of fibers and minerals. Here, we: (1) report the development of new products that offer improved performance, (2) compare the performance of these new materials with that of a range of other nanocellulosic material types, (3) illustrate the performance of these new materials in reinforcement (paper and board) and viscosification applications, and (4) discuss product form requirements for different applications.


1991 ◽  
Vol 23 (1-3) ◽  
pp. 201-209 ◽  
Author(s):  
W. Kreisel

Water quality can affect human health in various ways: through breeding of vectors, presence of pathogenic protozoa, helminths, bacteria and viruses, or through inorganic and organic chemicals. While traditional concern has been with pathogens and gastro-intestinal diseases, chemical pollutants in drinking-water supplies have in many instances reached proportions which affect human health, especially in cases of chronic exposure. Treatment of drinking-water, often grossly inadequate in developing countries, is the last barrier of health protection, but control at source is more effective for pollution control. Several WHO programmes of the International Drinking-Water Supply and Sanitation Decade have stimulated awareness of the importance of water quality in public water supplies. Three main streams have been followed during the eighties: guidelines for drinking-water quality, guidelines for wastewater reuse and the monitoring of freshwater quality. Following massive investments in the community water supply sector to provide people with adequate quantities of drinking-water, it becomes more and more important to also guarantee minimum quality standards. This has been recognized by many water and health authorities in developing countries and, as a result, WHO cooperates with many of them in establishing water quality laboratories and pollution control programmes.


1993 ◽  
Vol 27 (9) ◽  
pp. 47-53 ◽  
Author(s):  
N. F. Nicholson

Life, health and hygiene all depend on access to a plentiful supply of safe drinking water. Piped water supplies in rural Egypt are insufficient to meet the demands of the existing population. This situation is worsening due to the rapid population growth and failure of existing water supply systems. There are already areas of the country with severe piped water shortages. If corrective action is not taken soon densely populated villages will become vulnerable to outbreaks of waterborne diseases. Immediate action is needed to reverse the deterioration of water supply systems and to improve the benefits gained from capital works investments in the sector. This paper promotes the concept that sustainable water systems in rural Egypt depends on a central government and local unit partnership. Also needed are consumer bodies to determine user needs; local units to be given powers to manage the revenue and expenditure accounts; and the central government to concentrate on setting policies and guidelines, and assisting with the implementation of major capital works.


2011 ◽  
Vol 14 (2) ◽  
Author(s):  
Thomas G Koch

Current estimates of obesity costs ignore the impact of future weight loss and gain, and may either over or underestimate economic consequences of weight loss. In light of this, I construct static and dynamic measures of medical costs associated with body mass index (BMI), to be balanced against the cost of one-time interventions. This study finds that ignoring the implications of weight loss and gain over time overstates the medical-cost savings of such interventions by an order of magnitude. When the relationship between spending and age is allowed to vary, weight-loss attempts appear to be cost-effective starting and ending with middle age. Some interventions recently proven to decrease weight may also be cost-effective.


2000 ◽  
Vol 35 (2) ◽  
pp. 169-175 ◽  
Author(s):  
Robert A. Quercia ◽  
Ronald Abrahams ◽  
C. Michael White ◽  
John D'Avella ◽  
Mary Campbell

A pharmacy-managed anemia program included distribution and clinical components, with the goal of making epoetin alpha therapy for hemodialysis patients more cost-effective. The Pharmacy Department prepared epoetin alpha doses for patients in unit-dose syringes, utilizing and documenting vial overfill. Pharmacists dosed epoetin alpha and iron (oral and intravenous) per protocol for new and established patients. Baseline data were obtained in 1994, one year prior to implementation of the program, and were re-evaluated in 1995 and 1998. Cost avoidance from utilization of epoetin alpha vial overfill in 1995 and 1998 was $83,560 and $91,148 respectively. In 1995 and 1998, cost avoidance from pharmacy management of anemia was $191,159 and $203,985 respectively. The total cost avoidance from 1995 through 1998 was estimated at $1,018,638. The number of patients with hematocrits under 31% decreased from 32% in 1994 to 21% and 14% in 1995 and 1998 respectively. We conclude that a pharmacy-managed anemia program for hemodialysis patients results in significant cost savings and better achievement of target hematocrits.


Author(s):  
Allan Matthews ◽  
Adrian Leyland

Over the past twenty years or so, there have been major steps forward both in the understanding of tribological mechanisms and in the development of new coating and treatment techniques to better “engineer” surfaces to achieve reductions in wear and friction. Particularly in the coatings tribology field, improved techniques and theories which enable us to study and understand the mechanisms occurring at the “nano”, “micro” and “macro” scale have allowed considerable progress to be made in (for example) understanding contact mechanisms and the influence of “third bodies” [1–5]. Over the same period, we have seen the emergence of the discipline which we now call “Surface Engineering”, by which, ideally, a bulk material (the ‘substrate’) and a coating are combined in a way that provides a cost-effective performance enhancement of which neither would be capable without the presence of the other. It is probably fair to say that the emergence and recognition of Surface Engineering as a field in its own right has been driven largely by the availability of “plasma”-based coating and treatment processes, which can provide surface properties which were previously unachievable. In particular, plasma-assisted (PA) physical vapour deposition (PVD) techniques, allowing wear-resistant ceramic thin films such as titanium nitride (TiN) to be deposited on a wide range of industrial tooling, gave a step-change in industrial productivity and manufactured product quality, and caught the attention of engineers due to the remarkable cost savings and performance improvements obtained. Subsequently, so-called 2nd- and 3rd-generation ceramic coatings (with multilayered or nanocomposite structures) have recently been developed [6–9], to further extend tool performance — the objective typically being to increase coating hardness further, or extend hardness capabilities to higher temperatures.


2021 ◽  
Vol 6 (1) ◽  
pp. e000561
Author(s):  
Ving Fai Chan ◽  
Fatma Omar ◽  
Elodie Yard ◽  
Eden Mashayo ◽  
Damaris Mulewa ◽  
...  

ObjectiveTo review and compare the cost-effectiveness of the integrated model (IM) and vertical model (VM) of school eye health programme in Zanzibar.Methods and analysisThis 6-month implementation research was conducted in four districts in Zanzibar. Nine and ten schools were recruited into the IM and VM, respectively. In the VM, teachers conducted eye health screening and education only while these eye health components were added to the existing school feeding programme (IM). The number of children aged 6–13 years old screened and identified was collected monthly. A review of project account records was conducted with 19 key informants. The actual costs were calculated for each cost categories, and costs per child screened and cost per child identified were compared between the two models.ResultsScreening coverage was 96% and 90% in the IM and VM with 297 children (69.5%) from the IM and 130 children (30.5%) from VM failed eye health screening. The 6-month eye health screening cost for VM and IM was US$6 728 and US$7 355. The cost per child screened for IM and VM was US$1.23 and US$1.31, and the cost per child identified was US$24.76 and US$51.75, respectively.ConclusionBoth models achieved high coverage of eye health screening with the IM being a more cost-effective school eye health delivery screening compared with VM with great opportunities for cost savings.


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