Water Supply System

A safe and reliable water supply is an essential foundation for life and for continuing socio-economic development. Currently more than 800 million people throughout the world do not have access to even the barest recommended supply level of 20 liters per day within one kilometer of home. Approximately two-thirds of the populations lacking this minimum service level live in urban areas and projections of the impact of climate change suggest that the problem will deteriorate as more and more parts of the world become water-stressed. Coupled with the accelerating trend towards urbanization and the continuing unsustainable use of increasingly scarce water resources for disposal of wastewater, the need for action to better manage water resources is imperative.

NJS has been providing consultancy services in the water supply sector for almost 60 years, initially in Japan and latterly in a range of countries across the world. Experience has been gained in regional and small scale rural schemes using, for example, protected springs and hand pumps, in groundwater development in desert areas, and in major urban schemes incorporating sophisticated treatment technologies. NJS also has experience in the design of water reuse systems using tertiary treated wastewater for municipal, agricultural and industrial purposes. As in resource development planning, demand projections, tariff studies, affordability assessments, operation and maintenance and institution capacity building. An increasing number of the water supply projects managed by NJS include technology transfer and long-term training to the supply entity staff in all functional areas such as water quality analyses, trouble shooting, preventive maintenance, billing and collection and reduction of unaccounted for water.

NJS is experienced in assisting clients select the water supply system most appropriate for the project area, not only within the context of the engineering of the resource development, but also taking into account the wider ramifications of longer-term impacts on resource availability, and the opportunities for optimizing use through, for example, demand management techniques. In situations where water resources are constrained it is no longer appropriate to restrict project development technical issues, a more holistic approach is needed to ensure that the water supply system is sustainable and capable of being operated and maintained by the appropriate entity tasked with this responsibility.


Sanitation and Sewerage

Safe disposal of human wastes is a prerequisite for safeguarding both public health standards and environmental quality. Uncontrolled discharge of wastewater from households, industries and urban areas can give rise to pollution of receiving waters, resulting in potentially serious consequences for downstream water uses such as potable supply, commercial fisheries, irrigation, water-contact recreation or maintenance of the natural fauna and flora of the water body. Indiscriminate disposal of sludge from wastewater treatment plants or septic tanks can also give rise to serious public health hazards, either from pathogens or toxic elements present in the sludge. At the individual household level, indiscriminate defecation or poorly designed and maintained latrines are a major cause of ill health. It is estimated that more than 2 billion people were still without an acceptable means of excreta disposal in 2005 and that many more were served by systems that gave rise to unacceptable pollution of the receiving water.

NJS has been active in wastewater and sanitation for almost 60 years and over this period has carried out more than 18,000 projects in this sector encompassing the full range of sanitation technology, from rural schemes with improved latrines, slum upgrading, conversions of nightsoil and septic tank systems to regional sewerage systems and wastewater treatment ranging from on-site disposal, stabilization lagoons and mechanized processes including innovative membrane and tertiary processes designed to treat the wastewater to a level suitable for reuse. NJS’ experience in sludge treatment and disposal includes regional facilities for tankered sludge from septic tanks as well as composting, dewatering and incineration. Sewerage experience includes separate and combined systems, deep tunnel interceptor sewer tunnels, marine outfalls and shallow sewerage serving low cost developments.

NJS is experienced in assisting clients select the sanitation upgrading system most appropriate for the project area, taking into consideration local site conditions, cultural characteristics of the system users, affordability and the degree of technical complexity to ensure that the system will be long-lasting and will not place unachievable expectations on the system operators.

Solid and Hazardous Waste

The urban population of the world is projected to reach 5 billion people by year 2030. A reliable cost effective means of collecting and disposing of the solid waste generated by this population, as well as the potentially hazardous wastes generated by the industries that will continue to develop to service this population is essential. The current campaigns to reduce per capita waste generation and to maximize waste recycling will inevitably be extended and expanded in an attempt to optimize resource use and enhance resource conservation. Technological solutions alone will not solve the solid waste problem; there is a need for changes in cultural attitudes to waste production and a greater social cohesiveness to address the issues on a community wide basis.

NJS has been providing consultancy services in the solid and hazardous waste sector since its formation in 1951. From its early experience with waste incineration and nightsoil/septage treatment in Japan the company has carried out a diverse range of projects in this sector across the world. Project examples include waste minimization and clean technology for industrial estates, engineered sanitary landfills including their regeneration for community uses after closure, optimization of waste collection practices including transfer stations, waste segregation, incineration, and composting. In addition to providing design and construction supervision services, NJS also specializes in waste arising surveys, waste generation, operation and maintenance, technology transfer and staff training.

The recommended waste management system must be chosen to suit the particular local circumstances. Waste characteristics and disposal site conditions are only two of the factors that must be considered, different waste management and disposal strategies pose different degrees of technical complexity and these aspects need to be evaluated in the context of the socioeconomic level and culture of the users. Solid waste sector projects carried out by NJS include such assessments to ensure system sustainability.


Storm Drainage and Flood Control


NJS has been actively involved in the implementation of storm drainage and flood control systems in both developing and highly developed countries since its inception in 1951. NJS' experience in this sector ranges from hydrologic/hydraulic modeling to the design of drainage and flood control infrastructure such as stormwater detention reservoirs, collection drains, debris basins, pumping stations, outfalls, dikes, floodways, diversion channels including river channel widening and erosion protection measures. Projects have included both hard and soft engineering solutions, typical examples being the use of slow drainage concepts such as the adoption of urban streets as shallow drainage ways, temporary interception of roof drainage from individual properties, conjunctive use of sports areas as water meadows and swales during flood events, and the use of absorbent materials for car parks so as to increase retention times.

NJS also specializes in the development of flood projection models, flood damage assessment surveys for both direct and indirect (intrinsic) damages, and formulation of storm drainage and flood control and management systems as well as institutional and capacity development training for the transfer of technology adaptable to local conditions. Examples of NJS' experience in this sector include the widespread use of affordable

NJS Consultants Co., Ltd.

Head Office,Tokyo

  1-1-1, Shibaura, Minato-ku, Tokyo 105-0023 Japan