NDMA Removal and Reformation Prevention

N-nitrosodimethylamine (NDMA) is a potent carcinogen and historically was associated with the production of rocket fuels until the mid 1970s, as an antioxidant additive for lubricants, and as a softener of copolymers in the rubber industry. It is also found in trace amounts in cured meat products such as bacon and smoked fish. The additional lifetime cancer risk of 1 in 1,000,000 in humans is estimated to be posed by a 1.4 part per trillion (ppt) concentration in drinking water. The California Department of Health Services (DHS) has established an action level of 10 ppt.Orange County Water District (OCWD) detected NDMA in two drinking water supply wells in excess of the 10 ppt action level and in reclaimed water from Water Factory 21 “ treated through lime treatment, recarbonation, and filtration followed by either granular activated carbon (GAC) or reverse osmosis (RO)” in levels exceeding 100ppt. Analysis of NDMA data collected over a period of one year for each unit process at Water Factory 21 indicated that NDMA is not removed by these advanced treatment processes to any appreciable levels. This evaluation also indicated that cellules acetate and thin film composite RO membranes NDMA removal efficiencies are