8.1 Economic and financial implications
8.2 Institutional organization
8.3 Policy issues
While the overall benefits of wastewater use in agriculture are obvious and the technology and expertise exist to allow it to be achieved without detriment to public health or the environment, governments must be prepared to control the process within a broader framework of a national effluent use policy forming part of the national plan for water resources. Lines of responsibility and cost allocation formulae have to be worked out between the various sectors involved: local authorities responsible for wastewater treatment and disposal, farmers who will benefit from any effluent use scheme and the state which is concerned with the provision of adequate water supplies, protection of the environment and the promotion of public health. Sufficient attention must be given to the social, institutional and organizational aspects of effluent use in agriculture and aquaculture to ensure long-term sustainability.
Although the responsibility for collecting, treating and disposing of urban wastewater will normally lie with a local water or sewerage authority or municipality, farmers wishing to take advantage of the effluent are often able and willing to pay for what they use but are not prepared to subsidize general disposal costs. They will base their decision on whether or not they will be better off paying for the effluent rather than doing without it, taking into account the quantity, timing, quality and cost of the treated effluent. The local sewerage authority should acknowledge their financial responsibility for the basic system to achieve environmental protection objectives and only charge farmers for any incremental costs associated with additional treatment or distribution required specifically for effluent use in agriculture or aquaculture. In practice, if the effluent use scheme is considered at the time the sewerage project is being planned, treatment costs might well be reduced over those normally required for environmental protection.
Payments by farmers might take the form of direct effluent use tariffs paid to the authority, or contributions to the capital and/or operating costs of the wastewater treatment plant and effluent conveyance system. Cost sharing can be by cash payments or in-kind contributions, such as land for siting treatment or storage facilities and labour for operation and maintenance. Bartone (1986) has indicated that benefit-cost studies made in Peru showed that the irrigation components in effluent irrigation schemes were economically viable even if land costs and operation and maintenance for wastewater treatment were charged to farmers but not if the full cost of investment in treatment facilities was charged against the agricultural component. In the latter case, feasibility depended on the alternative minimum cost of treatment required for disposal without reuse.
Since wastewater treatment is a major cost in effluent use systems, accepting that local authorities are fully responsible for wastewater collection, it is essential that treatment process selection is made in conjunction with decisions on crop and irrigation system selection. Only in this way can a minimal investment in treatment be achieved without compromising the health risks of an effluent use scheme. Once a decision on effluent quality has been taken, the required standard must be achieved consistently and the effluent treatment and conveyance system must be operated with complete reliability. Fluctuating production and demand for effluent created by seasonal and diurnal patters of water use, cropping and crop water needs must be accommodated at all times, even if the price of the effluent is varied, to be higher in the hot season.
The scope and success of any effluent use scheme will depend to a large extent on the administrative skills applied. Wastewater collection and treatment and effluent use in agriculture and aquaculture span a wide range of both urban-based and rural-based interests at both local and regional levels and institutional responsibilities must be clearly defined. Decisions will have to be taken on:
- allocation of effluent among competing uses,
- maintenance of quality standards and system reliability,
- investment in supporting resources, especially managerial and technical staff, required to administer each component of an effluent use scheme.
Policy decisions should normally be taken by a national or regional body, with executive responsibilities in the hands of a regional organization. Such a regional organization would be responsible for project implementation and operation and would provide the criteria, framework and administrative mechanisms necessary for effective effluent utilization. However, they would also be responsible for effective monitoring and control of the crops irrigated, the quality of effluent and associated health and environmental impacts.
One of the most important features of a successful effluent use scheme is the supervision provided at all stages of the system. Strict control must be applied from the wastewater treatment plant, through the conveyance and irrigation systems to the quality of the resulting products, whether they are of commercial or environmental value. The management, monitoring and public relations procedures are as important as the technological hardware involved in the system and managers of regional organizations set up to administer effluent use projects must be firm if the schemes are to realise their full potential. Managerial and technical staff must be properly qualified and suitably trained to carry out their functions effectively. Treated effluent use in agriculture is a major resource development activity and requires an appropriate institutional structure, provided with adequate resources, to be successful.
The legislative framework for effluent use in agriculture can have a significant influence on project feasibility. Bartone (1986) has indicated that the authorities in Mexico are able to impose effective crop restriction measures in Irrigation Districts because they are empowered to withhold effluent from farmers not observing the regulations, whereas in Chile the sanitary authorities have little leverage. Chilean Water Law vests water rights in the farmers (landowners) and the authorities have never been successful in imposing crop restrictions, even though lettuce and other vegetables being irrigated with raw sewage have been implicated in annual typhoid epidemics in Santiago.
A coherent national policy for wastewater use in agriculture is essential. This must define the division of responsibilities among involved ministries and authorities and provide for their collaboration. Institutional mechanisms for implementation of the national policy must be established and legal backing provided for enforcement of regulations. Realistic standards must be adopted to safeguard public health and protect against adverse environmental impacts. Environmental issues associated with wastewater use are the main subject of a UNEP (1991) document. Provisions should be made to adequately staff and resource organizations charged with the responsibility for assessing, implementing, operating and monitoring effluent use schemes and enforcing compliance with regulations. A distinction between the upgrading of existing wastewater use schemes and the development of new schemes is drawn in Mari and Cairncross (1989). In addressing the former, it is stressed, attention should be paid not only to the technical improvements required or feasible but also to the need for better management of existing schemes and to their improved operation and maintenance.
A national and/or regional consultative committee will often be of value in developing policy guidelines. Serving on this committee should be a representative of all the main interest groups, including water resources planning, public health, public works (municipalities), agriculture and forestry, environmental protection, trade and commercial interests (including farmers' representatives). Policies emanating from such a committee should be free of local or partisan influences but, nevertheless, should be pragmatic. In particular, enforcement legislation must be unequivocal, unambiguous and addressed to the main problem areas. The committee should also be charged with assessing the epidemiological and agricultural impacts of effluent use schemes.