This final chapter summarizes existing sanitation and environmental problems in coastal and waterfront communities and those on low-lying areas, enumerates the important considerations for the provision of sanitation systems in these communities, and identifies the feasible sanitation systems. It also provides general recommendations for future studies related to this research.
7.1 Summary of existing sanitation Problems
Findings from the literature review of several examples of coastal communities presented in Chapter 2 linked health and environmental problems to a lack of sanitation facilities. In coastal and waterfront communities, disposal of the human waste into the surface water or ground without treatment is prevalent. This traditional habit has become unhygienic since there are cases wherein the surface water is also the source of water for drinking as well as for personal and domestic cleaning. Such practice is also becoming questionable in communities with increasing densities. In other communities, the surface water is stagnant, thus the pollution problem increases. Aggravating this problem is the disposal of other domestic wastes, specifically wastewater and solid waste, both bio-degradable and nonbiodegradable, into the surroundings.
The analysis of sanitation in the coastal communities of Puerto Princesa derived similar findings. In the absence of sanitation facilities, particularly in houses built on the transition and water zones, disposal of human waste without treatment into the mudflat and bay is the common practice. It is favorable that the water of the bay is not consumed for drinking. However, disposal of excreta without treatment is not justified, especially in the transition areas where accumulated solid waste obstruct natural flushing of the waste by the current, thereby leaving the excreta exposed.
With health and environmental problems arising due to unsanitary conditions in these communities, what are the alternatives for disposing of human waste safely? In providing sanitation systems, what are the essential factors to be considered? In identifying the key considerations for the provision of low-cost sanitation systems in coastal communities, it is necessary to analyze the environment, community structure and available services such as water supply, collection of waste water and solid waste. In this analysis, the classification of the coastal environment into three zones defined in Chapter 5 is used as an important tool to be able to identify the problems clearly. These zones include the dry, transition and water zones, which are based on the location of the houses within the coastal site. Through this analysis, it was derived that existing conditions and the essential consideration for the provision of sanitation systems vary among the three zones.
7.2 Key Considerations in the Provision of Sanitation Systems
The derived key considerations include environmental factors and community- specific physical, social and cultural factors. Environmental requirements such as the condition of the surface water and ground conditions are the preliminary considerations. The condition of the surface water determines the acceptability of disposing of untreated human waste into the surface water. The prevention of such a practice becomes urgent when any of the following conditions occurs:
- community density is high in relation to the natural threshold of the surface water;
- surface water is consumed for drinking by the community;
- feces are deposited on the ground and not directly into the water; and
- surface water is stagnant or there is not enough current or tide to disperse and dilute the waste.
In determining alternative means to dispose of human waste, the basic problem with the provision of sanitation facilities in coastal communities, as illustrated in the literature review and case study, is the adverse ground conditions of the site. The site of these communities is characterized by the low permeability of the soil, and the high groundwater level to the extremes of presence of surface water. Technically, this condition inevitably limits sanitation options to those which require off-site treatment of waste or those which can be built above the ground.
Other essential factors affecting the choice of sanitation systems include the available services within the community such as water supply service levels, the means of disposing of wastewater and solid wastes, and the access networks within the community. Water supply is limited in most coastal communities. Sullage or wastewater collection does not exist, hence they are disposed of into the ground or surface water without treatment. Garbage collection is also a problem, thereby increasing the pollution of the water. Circulation networks within the community consist mainly of narrow footpaths and walkways on stilts, making access for collection of waste difficult. Whichever sanitation systems are considered feasible, based on the considerations discussed above, should however, be socially and culturally acceptable to the users.
7.3 Recommended Approach in the selection of Sanitation Systems
With the essential considerations for the provision of sanitation systems in coastal and waterfront communities identified, two general stages of selections are recommended. The first stage involves the selection between communal or individual toilets. Communal facilities involve the construction of several toilets built in one location, shared by a number of households, while individual facilities refer to the construction of toilets for each household. The second stage is determining the appropriate means to dispose of and treat the human waste, whether through individual household or community network sanitation systems. Individual household system involves on-site treatment of waste. Community network, on the other hand, involves a collective system, in which waste is collected from several households and transported to another site for treatment. The important considerations for both stages are summarized below.
Stage 1: Communal Toilets vs. Individual Toilets
Provision of communal toilets has been considered the most common and technically feasible approach, as in the cases of the coastal communities reviewed and in the case study. For the local government and project planners, provision of these facilities simplifies the problem since the toilet blocks can be built on more stable areas, particularly on sites with favorable ground conditions where there are more feasible options for the treatment of waste. This approach however, proved a failure in most of the coastal communities reviewed due to poor access and the proximity of the facility to users and poor maintenance. When this option is preferred, the considerations discussed below must be assessed well.
A critical aspect in the planning stage of providing communal toilets in coastal communities is determining the most strategic location of the facility, considering accessibility and proximity to the users. In most cases, a large percentage of households in the communities has encroached on the water, so that their proximity to the ideal sites for the facility is decreased.(1) As analyzed in the case study, toilet blocks are located at elevated areas where it is easier to provide excreta disposal system. Thus, determining the most strategic location for the facility involves the analysis of trade-offs between user accessibility and convenience and the cost of the facility.
Compounding the difficulties with the provision of communal toilets are usage and maintenance problems. Public toilets seem to belong to no one and thus there is very little commitment by the individual users to keep it clean and operating properly.(2) Provision of communal toilets requires a high level of maintenance for proper operation. A well-organized community group can be an important tool for this requirement. This can be achieved by assigning the facility to a group of households who will use and maintain it exclusively. Grouping the households based on extended families and/or camaraderie among neighbors is effective.
Provision of individual toilets, on the other hand, involves a more complex set of requirements, since it is difficult to provide excreta and effluent treatment means for toilet facilities built above the water and mudflats or other low-lying areas with high groundwater level. In a prototypical coastal community, as in the case study, conditions vary in each zone, hence technical modifications and adaptations should be made depending on the specific location of the proposed toilet. The selection of waste treatment and disposal systems are discussed below.
Stage 2: Selection of Sanitation Systems
Considering the environmental and community physical factors common in coastal communities, requirements for sanitation systems can be summarized as follows: feasible in areas with adverse ground conditions, specifically impermeable and unstable soils with high ground water; feasible in high density areas; requires minimum water; and does not require large equipment for waste collection and transportation.
The adverse ground conditions inevitably restrict the use of on-site or individual sanitation systems that require favorable ground conditions. As manifested in the use of the septic tanks in kampung settlements in Jakarta and in the coastal communities of Puerto Princesa, the problems associated with the use of this technology include the following: poor permeability and high groundwater level, resulting in non-functioning of the system; contamination of groundwater, especially sources of drinking water, which eventually result in the transmission of diseases.
In dealing with high groundwater level, some on-site systems are technically feasible, namely: the double pit and raised pit latrines; the cesspool as used in the klong settlements of Bangkok, Thailand; and the Vietnamese composting toilets. Important considerations in the construction of improved versions of the pit latrine are the prevention of contamination of nearby water supplies and their application only in low-density settlements. With cesspools, although originally designed for areas with high groundwater level, the access of toilets for regular collection of sludge is required. For composting toilets, which can be contained above the ground, water infiltration into the vault must be prevented; wastehandling and a high degree of user care and attention are required.
Because on-site technologies are individual household systems, it is difficult to provide toilet in houses built above the waters. The improved versions of the pit latrine and the cesspool, which rely on soil infiltration are definitely not feasible in the waterzone. No field report supports the actual construction of composting toilet tanks above the water, and therefore this requires further research to check its feasibility.
Off-site systems such as the bucket latrines, the vault and cartage, the shallow sewer and the small bore sewer are feasible. The bucket latrine is used in coastal communities as in the case of the watertowns in China. This option, however, requires that waste re-use be a great demand in the community and that excreta-handling be socially and culturally acceptable. The vault and cartage system is theoretically feasible but no documentation supports its actual application in coastal communities. Like the composting toilets, the prevention of water infiltration into the tank is critical in the construction of the vault on ground with high groundwater level. The application of the vault and cartage system in the waterzone requires innovation and further study.
The two modified versions of the conventional water-borne sewerage, namely the shallow sewer and the small bore sewer systems, are two feasible options in coastal communities. These systems can be built on sites with adverse ground conditions, they require minimum water, they can be applied in high density areas and they do not require access for large trucks or equipment for the collection of waste. The shallow sewer system is applicable in the three zones, since the small diameter sewer lines can be laid down on shallow trenches and can extend underneath the walkways above the water. With this option, pour-flush toilets can be built above the water with the small diameter sewer collecting the waste. The sewer lines can then be connected to the main sewer, if available, or to a communal septic tank built on more favorable ground for waste treatment. The small bore system, on the other hand, can upgrade the existing septic tanks and make them function properly, by connecting the tanks with small diameter sewer lines. However, this system cannot be applied on the water zone, since construction of tanks above the water is not feasible. One approach is to apply the shallow sewer in the water zone and connect it to the small bore sewer system in the dry and transition zones.
The sanitation systems, identified as options based on the preliminary considerations developed in this thesis, cannot be considered completely feasible in any coastal or waterfront site. Since a sanitation program is on a project-to-project basis, special considerations and modifications of options may be necessary, depending on the requirements of a specific community. From this preliminary selection phase, community specific economic, social, cultural and institutional requirements should be considered before the final selection is made and before the selected option is implemented.
7.4 Final Remarks
In the overall analysis of the existing sanitation and environmental conditions of a prototypical coastal community, it has been observed that the closer a household is to the waterzone, the more adverse the ground conditions become, and the more limited community services are in terms of access and circulation networks, water supply, wastewater and solid waste collection. Under these conditions, the sanitation options are decreased.
The approach to improve sanitation conditions in coastal and waterfront communities and those in low-lying areas may involve more than one option or a combination of two or more systems, depending on the location of the proposed facility within the coastal site. In some cases, it may be necessary to use less perfect solutions that can be incrementally improved as other existing services are improved and those lacking are provided. Household connections for the water supply, for instance, can be made available in some areas of the community if it is necessary to make one sanitation system feasible. Walkways and circulation networks can be upgraded to allow small carts to pass through to provide access for waste or sludge collection and transportation. In cases where access improvement is not possible, improvisation of collection vehicles can be done, such as small hand-drawn or animal driven carts that can pass though the existing walkways. The trade-off among these options will have to be studied properly.
In any sanitation program, technologies may be identified as appropriate, but if the application does not involve information, training of community members and mobilization, the project will be a failure. Many sanitation programs are planned and executed by government bodies, and few are successful due to the failure to convince and educate the people of the importance of sanitation and the need for an active cooperation.(3) Education factors play a very important role because it is only through the basic understanding of the need for sanitation can the people be mobilized for its implementation.(4) Critical to the coastal communities is the need to inform the community members about the health and environmental hazards caused by their traditional practice of defecating on the surface waters. It is only when they understand the consequences of the unsanitary conditions they have that they will be willing to change their habits.
When new sanitation technologies are introduced, planners must find ways to bring the project into balance with community knowledge, attitudes and behaviors relating to health and sanitation.(5) The proposed system should not be too complicated for the user to operate and maintain. It should not require radical behavioral changes that the community will eventually reject it. And most importantly, community training provided will ensure that the skills required to construct and operate the improved facilities are within the local capability. These requirements emphasize that usage and sustainability are critical to the success of sanitation projects. Unless facilities are suitable for the people using them and unless the technologies are affordable and efficient, the facilities will remain unaccepted and underused.(6)
1. In worse conditions, as manifested in the case of Barangay Matahimik, the local government provided only one toilet block, consisting of six stalls. Households located within the water zone travel more than 400 meters to reach the facility.
2. Kalbermatten, et. al., p. 140.