   
|
| xxxformerly Center for Ecological Polution Prevention |
|
Ecological
Wastewater Management: Creating Resources, not Pollution | |||||
Wastewater
Management for the Islands: [Note: Only a few photos are posted here, due to slow load times. Click here to see gallery of some photos.] Presentation, Fiji Ecotourism Association conference December 2000 ¥ Nadi, Fiji Carol
Steinfeld David
Del Porto [text corresponds to slide presentation]
What's at Stake:
Chuuk Polluted Beach This situation is a reminder of what's at stake when waste is not well managed: not only is human and environmental health compromised, but tourist attractions can also be spoiled. The answer is to use systems that divert potential pollutants from the environment. The easiest way to do that is to use them up. The following are some examples of ecological systems, with an emphasis on strategic utilization and the simpler on-site aerobic systems (because our organizations have a history with these systems in the Western and South Pacific islands). Lalati
Resort, Beqa Island, Fiji They had seen a community composting toilet that Sustainable Strategies had built with the Fiji School of Medicine outside of Suva. Based on this, they asked the firm to design a system for an upscale resort with low-cost, locally available materials and with flush toilets--one that could be maintained by the resort staff. The result was this system:
The staff of Lalati adds coconut coir every few days. When a composting reactor fills (with this small size, this takes anywhere from 3 months to 1 year), it is taken to a covered central area to further process. In six months, the material should be fully processed and ready to be added to a composting pile to further process or to be applied to soil. (Although this resulting humus should be pathogen free, we do not advocate its use on edible crops.) Lalati's owners like the fact that the system does not pollute the coastline (and the very sites that attract clients) and that it is maintained by the resort staff. They also enjoyed significant cost savings over a septic system. Guests, they say, appreciate knowing that their accommodations employ such an ecologically responsible system. This system illustrates the good economics of the ecological approach. The Ecological Approach Advantages:
How: Conserve, Pretreat, Divert/Separate, Reuse/Reclaim
* Pretreat Filter at the source to remove larger particles so it can be used by plants. In kitchens, use grease and food interceptors. Disinfect with ozone or UV if to be used for potable water. * Divert/Separate wastewater components By keeping flows separate, they can be better and more cost-effectively treated and utilized. * Reuse or reclaim 2. Reclaim it for other use: Flushing toilets and urinals, washing, etc.
El Santuario, Baja California
Sur, Mexico Its owners needed a water-conserving system that would be acceptable to their guests. CEPP, using designs from Sustainable Strategies, designed small aerobic blackwater biofilter (enhanced composting toilets) with attractive blue urine-diverting toilets made in Mexico. A larger system was built for an adjacent area used for camping by kayak groups. A Wastewater Garden was built for the kitchen, and a system that combines urine from the urine-diverting toilets and washwater from showers and sinks drains to a lined planter bed, which grows hibiscus and other tropical plants that serve as a privacy barrier. The initial construction took place as part of a three-day ecological wastewater workshop attended by builders and Harvard School of Public Health graduate students. Rock
Islands, Palau (Micronesia) Sustainable Strategies designed larger systems, using Carousel enhanced composting toilets based on a Norwegian design that has proven most successful in studies in Scandinavia and the United States. Each unit contains four chambers that are used interchangeably as they fill up. This batch approach speeds the biological decomposition process and allows for full biological decomposition, so that what is removed is a fully processed and stable end-product called humus. Extra liquid from the process is drained to Wastewater Gardens located between the two toilet rooms. This system is now being considered for installation in homes in Palau. Greenpeace Toilet, Yap (& Kosrae and Pohnpei, Micronesia) This system, now often called "the Greenpeace Toilet" (although its design has been simplified; this newer version is called the "CEPP Twin-Bin with Net Composting Toilet System"), was constructed with YapCAP on an outer island for use by a household. In this system, one side is used at a time. When one chamber fills up, it is capped and the other side is made active. When this one has filled, the other side can be emptied. At this point, what is removed is a stable soil-like humus, which can be used as a soil conditioner. It is usually five years before the first chamber is emptied. Improving on past designs, Sustainable Strategies optimized the aeration features and engineered air-intakes and exhaust chimney sizes that promote air and vapor throughput without power. A follow-up visit to the three islands in 1997 found that the site-built system had been most successfully adopted in Pohnpei, where the local utility was involved in its promotion. On Pohnpei, several systems had been independently built, including one for visitors to Nan Madol, an ancient stone city. Fiji and Samoa Community Systems
(Drawbacks) Visiting in December 2000, we found that it was not used regularly as it was deemed too special for regular use. This is unfortunate, as it was constructed for high-volume capacity. This is a common problem with systems that are "given" to communities without demand by the community and more involvement. This underlines the need for community-based introduction and management programs. In 1999, CEPP sold the plans for this system to Habitat for Humanity Fiji. It was built by an American mission group, which left off several features due to time limitations. As a result, the system produced odors. It was ultimately closed by the Fiji health department because necessary approvals for construction had not been secured. Our experiences suggest that ecological sanitation systems are best modeled by willing owner-operators--but not built as service projects at the homes or community sites of ambivalent users. Ultimately, the implementation program is as important as good design. These two experiences, as well as similar ones in Western Samoa, have prompted the Center for Ecological Pollution Prevention (CEPP) to cease selling the plans, only making them available to community-based organizations through the Pacific EcoSan Center. Western Samoa United States Maintenance involves adding some chunky carbon every week. This owner uses a cup of bark every day. These systems are increasingly installed in upscale homes in the United States and other industrialized countries. Ecological Zero-Waste-Discharge Systems in the U.S.A. Sustainable Strategies designed a system much like the one for Lalati: integrated aerobic biofilters, source filtration and Wastewater Garden aerobic planting bed. In this system, the Wastewater Garden enclosed in a greenhouse (for warmth and to keep out precipitation--the warmer the system, the faster the biological transformation process). Sustainable Strategies has designed a wide variety of such zero-waste-discharge systems for homes, schools and other buildings in the United States. Next slide: Old
Manse historic home in Concord, Mass. One key to this approach is to filter and pretreat at the source. By keeping effluents separate--not combining them--they are more easily used. Besides the aerobic blackwater biofilter, other source filters include grease interceptors and 30-micron filters. Urine
Diversion Wastewater and Washwater
Gardens They can be indoor features (slide: Audubon Center indoor planter bed).
Washwater/Wastewater Gardens are like wetlands but drier, allowing for more aerobic activity, the faster processing. Pores in these systems provide homes for beneficial bacteria, which destroy pathogens and convert nutrients to a plant usable form. At the same time, the plants evapotranspire away the water. These ecological systems can be scaled up to serve clusters of homes and even full communities. Central Community Systems in U.S.A. Water is reclaimed for flushing toilets or it can be disinfected and used for washing. Water
Hyacinth Large Central System, U.S.A. Chuuk
Beach Hotel Sign Again (No Swimming in the Sewage!) | |||||
