A HOMEOWNERS GUIDE TO APPROACHING THE MAXIMUM CONTAMINANT LEVEL GOAL (MCLG) FOR ARSENIC OF 0 PPB – A CASE STUDY
This project investigates the long-term As occurrence in a private well in Orange County, North Carolina (the Piedmont) and the performance of different As treatment technologies to lower the arsenic level. The investigated private well has As levels of 4-8 ppb, however attempts were made to reduce the As to the MCLG of 0 ppb for the house. The study is based on As measurements by a high-resolution Inductively Coupled Plasma Mass-Spectrometry (ICP-MS) at Duke University with a detection limit of 0.005 ppb. This lower detection level enables us to monitor even small As variations in groundwater and the effectiveness of different treatment technologies for As remediation. In-home water filtration options included treatment with a whole house water softener, installation of a reverse osmosis system attached to the kitchen sink, small ferric iron filters installed along the inflow to the kitchen sink faucet, and a whole-house iron oxide filter. Multiple measurements made over a period of >1 y indicate that the granular ferric oxide media reliably reduces initial arsenic levels down to a zero arsenic level. The small point-of-use granular ferric oxide filters are easy to install and offer a cost-effective alternative to bottled water.