The objective of this work is to quantify the reduction of biofilm formation in a water distribution system resulting from an organoselenium surface coating on stainless steel pipes and fittings. Differentiated from currently marketed antimicrobials, selenium, is permanent, catalytic and does not leach into the environment. This will reduce the problems associated with biofilm growth and fouling in the water recycling system.. Thus, we could draw quantifiable conclusions about the system performance for long term missions in complex water treatment systems containing organoselenium coatings and provide the data to NASA engineers who may then make an assessment as to whether or not this is a viable technology to reduce the need for biocides, reduce ESM, and potentially impact NASA by decreasing the chemical burden for treatment which would decrease payload mass and downtime affecting astronauts' efficiency. The project will quantify the impact of an organoselenium surface coating within stainless steel pipes and fittings on product water quality and service life of the pipes and fittings over time. Objective 1. Optimize the attachment of organoselenium to the surface of stainless steel to achieve the greatest and most reliable reduction in biofilm growth and formation. Objective 2. Assess performance of the organoselenium surface treatment of stainless steel pipes and fittings in a bench-scale system over varied periods of time (i.e. 1 week, 1 month, 3 months) against biofilm accumulation and service capacity.