water quality monitoring and identification of contaminants. Difficulties in contaminant identification may include the separation of inorganic and organic pollutants, microorganisms, colloids, and others. Full cost recovery from water reuse schemes is difficult. There is a lack of financial water pricing systems comparable to already subsidized conventional treatment plants. Psychological barriers, sometimes referred to as the "yuck factor", can also be an impediment to implementation, particularly for direct potable reuse plans. These psychological factors are closely associated with disgust, specifically pathogen avoidance. Health aspects Reclaimed water is considered safe when appropriately used. Reclaimed water planned for use in recharging aquifers or augmenting surface water receives adequate and reliable treatment before mixing with naturally occurring water and undergoing natural restoration processes. Some of this water eventually becomes part of drinking water supplies. A study published in 2009 compared the water quality differences of reclaimed/recycled water, surface water, and groundwater. Results indicate that reclaimed water, surface water, and groundwater are more similar than dissimilar with regard to constituents. The researchers tested for 244 representative constituents typically found in water. When detected, most constituents were in the parts per billion and parts per trillion range. DEET (an insect repellant) and caffeine were found in all water types and virtually in all samples. Triclosan (in antibacterial soap and toothpaste) was found in all water types, but detected in higher levels (parts per trillion) in reclaimed water than in surface or groundwater. Very few hormones/steroids were detected in samples, and when detected were at very low levels. Haloacetic acids (a disinfection by-product) were found in all types of samples, even groundwater. The largest difference between reclaimed water and the other waters appears to be that reclaimed water has been disinfected and thus has disinfection by-products (due to chlorine use). A 2005 study found that there had been no incidences of illness or disease from either microbial pathogens or chemicals, and the risks of using reclaimed water for irrigation are not measurably different from irrigation using potable water. A 2012 study conducted by the National Research Council in the United States of America found that the risk of exposure to certain microbial and chemical contaminants from drinking reclaimed water does not appear to be any higher than the risk experienced in at least some current drinking water treatment systems, and may be orders of magnitude lower. This report recommends adjustments to the federal regulatory framework that