CALGARY, Nov. 24, 2016 /CNW/ - The National Energy Board (NEB) has declined a request from TransCanada PipeLines Limited to amend its tariff for the Storage Transportation Service, which is a service offered on the Canadian Mainline Gas Transportation system. Tariffs describe the terms and conditions under which the services of a pipeline are offered or provided. TransCanada applied to amend the tariff that applies to its Storage Transportation Service and Storage Transportation Service-Linked. These services allow shippers to move their gas to and from storage in order to manage both seasonal and daily fluctuations in their market demand. During the NEB's assessment of the application, TransCanada said that many of the existing contracts for Storage Transportation Service were negotiated individually, going back to the 1970's. As a result, there was a wide variation in the terms of the contracts signed by different shippers. TransCanada indicated that this made the transportation service overly complex, inconsistent and discriminatory. TransCanada submitted that the proposed changes would enhance consistency with the NEB's tolling principles of no unjust discrimination, cost-based user-pay, no acquired rights and economic efficiency. Some of the shippers who were intervenors in the hearing submitted that the impacts of the changes proposed by TransCanada were high. For example, total Mainline costs could increase by 27 per cent for Centra Gas Manitoba Inc. and by 30 per cent for Union Gas Limited. Intervenors also indicated that it would be unfair to make changes to the transportation service at this time. They suggested that the appropriate time to review changes to the Storage Transportation Service would be during the upcoming tolling application for post-2020 tolls when the segmentation of the Mainline would be considered. They submitted that, since long-haul firm transportation on the Mainline is likely to change at this time, Storage Transportation Service is also likely to change.