Sept. 3, 2002

Bruce Buckingham
Kennedy Space Center
321/867-2468

RELEASE: 79-02

NASA/KSC FINDS WAY TO TREAT WASTEWATER BEFORE RELEASE INTO GROUND, BENEFITING THE ENVIRONMENT

Most people don't think about where wastewater goes once it leaves the 
house, but scientists at Kennedy Space Center (KSC) are doing that 
now as they evaluate methods to clean water containing human waste 
before it ever reaches local groundwater. The cost-effective 
technology could be a boon to coastal areas and other locations. 

Dynamac Corporation is the KSC contractor responsible for life 
sciences support services and environmental and ecological monitoring 
of KSC's premises, located on a national wildlife refuge. Their work 
in wastewater treatment is a natural extension of the research team's 
efforts to develop closed, bioregenerative life support systems for 
long duration space missions.

In most residential areas without central sewerage systems, wastewater 
enters a leach field or drain field from a septic tank system. 
However, in areas with increased development and limited land, such 
as coastal areas with overly porous soil or impermeable rock strata, 
wastewater often finds its way into the groundwater and nearby 
surface water.

"It's a widespread problem in Florida, where the soil is very porous," 
said Dr. John Sager, a NASA scientist working at Kennedy and 
principle investigator on the wastewater research project. "That can 
lead to pollution, both in coastal areas and in the many freshwater 
lakes up the spine of the state."

This problem is all too familiar to residents and health officials in 
areas such as the Florida Keys. As the Keys continue to grow in 
population, the amount of land becomes more and more limited, leading 
to the pollution of nearby seawater. As a result, beaches in 
more-developed areas are often closed due to wastewater intrusion 
until the pollution subsides.

The solution to this problem is to make sure wastewater is treated 
before it is released into the groundwater. Although there are some 
treatment methods currently used, they are complex, time-consuming 
and can be expensive.

In the method proposed by the NASA/KSC team, plants will use the 
phosphorus and nitrogen, or nutrients, in the wastewater for their 
own nutrition and growth. The pathogens will be held in the soil and 
ultimately deactivated. The remaining clean water will be released 
through the plants' leaves in a process known as transpiration.

The work is being conducted at Hangar L, Cape Canaveral Air Force 
Station, the center of life sciences projects. Behind Hangar L, four 
large white boxes are topped by an attractive array of common Florida 
plants, including several varieties of palms and philodendrons. Each 
box acts as a contained drain field, receiving five gallons of 
simulated wastewater per day, or half the amount of wastewater 
created by one person.

Dynamac scientists Neil Yorio and Jay Garland pointed out that in a 
residential yard, the box would be buried, revealing only the thick 
stand of plants. The plants in use are salt-, flood- and 
drought-tolerant, making them well-suited for this tropical 
environment. A barrier hidden under a layer of mulch keeps rainwater 
from directly entering the soil.

Phase One of the three-phase project began in November 2001 and 
concluded in March 2002. After 105 days of testing, the plants 
thrived, showing no sign of toxicity to the high nutrient 
concentrations and bacteria in the water. Although the plants 
transpired less water during winter months than expected, this is not 
abnormal, especially when plants are still becoming established.

The team has seen a more rapid transpiration rate during the first 
three months of Phase Two, which began in April and will run for 
about a year. During Phase Three, the system will be tested in a real 
environment, although site selection is still in the planning stage.

"It's exciting to use the expertise we have developed for NASA to 
address a terrestrial problem," said Dr. Garland, a microbial 
ecologist. "The goal of developing sustainable human habitation 
systems is a transcendent challenge for Earth and space."

NOTE: A NASA TV Video file will be shown with B-roll and interviews at 
3 p.m. and 6 p.m. today. 

	
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