Disasters, Finances, Nutrients, and Climate Change: A Case for Waterless Sanitation Systems

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Ryan Smith

EXECUTIVE SUMMARY

Wastewater systems have arguably improved quality of life by protecting public health and the environment. They provide a method of sanitation that uses water to manage human excreta. However, extending the current wastewater paradigm is becoming problematic due to water’s increasing scarcity, mounting costs, contribution to greenhouse gas emissions, and deleterious environmental effects.

Water is the key element of wastewater conveyance, treatment, and disposal/reuse systems. Without it, these systems would not function. Wastewater systems generate greenhouse gas emissions, which contribute (in part) to climate change. Irregular precipitation patterns will affect the water supply; therefore, water scarcity will also affect wastewater systems through water conservation efforts and increased frequency of “day zero” occurrences. Additionally, increased storm intensity and rainfall will result in the increased number and volume of sewer overflows that discharge untreated wastewater into communities and the environment. Wastewater systems are also at great risk from flooding because many assets lie underground.

As a whole, wastewater infrastructure in the United States is deteriorating and needs significant upgrades. These necessary capital improvement projects are costly, as are the ongoing operations and maintenance costs over an asset’s lifetime. Local governments must finance these expensive infrastructure projects. Affordability challenges will only continue to increase as rising costs are passed through to users of a system.

Nutrients and nutrient pollution are also of concern. Humans consume food and excrete nutrients into wastewater systems. Aquatic environments that receive effluent from treatment systems that do not adequately remove these nutrients (namely nitrogen and phosphorous) suffer negative impacts such as from harmful toxic algae growth. Phosphorous is of particular importance because the world’s rock phosphate reserves are declining and are predicted to be depleted in the next hundred years.

With the above concerns in mind, does the United States need to upgrade its wastewater system, or should an alternative sanitation paradigm be considered? After all, using water to manage human excreta is one method of providing sanitation services, but not the only way. Research has revealed that ecological sanitation (EcoSan) is a philosophy that looks at this service holistically, considers the environment, and returns the nutrients in excreta to the soil. Various EcoSan technologies exist, and four human subjects who actively practice ecological sanitation were interviewed for this research. One method known as container-based sanitation is a process whereby urine and feces are deposited into a container (e.g., a five-gallon bucket) and covered with an appropriate material. Once full, the entire contents of the container are emptied into a composting system that produces a useable compost over time.

In sum, container-based sanitation is a proven method in multiple contexts. These circumstances would arise when neither water nor the wastewater systems (that rely on water in the first place) are available for use. These conditions apply under the following circumstances: disaster recovery, depressed socioeconomic conditions, and homelessness. Likewise, temporary tent cities and encampments and temporary military bases would also be appropriate uses. The beauty of container-based sanitation lies in its ability to rapidly scale up or down, depending on the need, which directly applies to disasters that result in large populations without access to safe sanitation.

Consistent with the findings, this thesis proposes the following recommendations:

  1. Incorporate container-based sanitation into disaster preparedness and response plans.
  2. Design and implement a pilot study for long-term, sustainable utilization of container-based sanitation.
  3. Permit container-based sanitation for people and communities lacking a traditional wastewater system, or with a failed one.
  4. Develop consistent regulations, policies, and guidelines across local and state jurisdictions to allow for container-based sanitation, the composting of human excreta, and the beneficial reuse of the compost.

 

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