IMO 159(55)/USCG NVIC 1-09 Sewage Treatment Plants from a Laboratory’s View Matthew D. MacGregor TEi-Testing Services, LLC Salt Lake City, UT - USA

Why Test The end state of any new regulations or devices meant to meet new regulations is the proof of compliance. This is done by initial qualification testing and continual compliance testing.

Initial Qualification Testing Initial qualification testing has two requirements, physical testing consisting of mechanical/electrical performance challenges. And influent processing testing to establish that the Device under Test meets effluent regulations.

Physical Testing The requirements for mechanical/electrical performance are based on the ability of a Sewage Treatment Plant (STP) to withstand the rigors of the marine environment to include corrosion, vibration, incidental impacts, etc.

Effluent Testing Processing testing is based on the ability of a STP to affect the basic composition of sewage which has physical, chemical and biological elements. Testing for these elements is done using three types of analysis; Physical, Chemical and Biological challenges.

Effluent Physical testing Consists of determining the amount of matter discharged in the effluent which is made up of the solid residues found in sewage such as fibrous, cellular and foreign material. Testing looks for the amount of Total Solids untreated by the STP and passed into the environment.

Effluent Chemical testing Consists of determining the amount of natural and introduced chemicals found in the STP influent. Chemical testing consists of determining the amount of natural and introduced chemicals found in the STP influent. These chemicals constitute what is known as bio-limiting nutrients and hazardous materials. Bio-limiting nutrients are naturally occurring in human waste and if untreated promote unwanted growth in an aquatic system. These bio-limiting nutrients are determined by testing for; Chemical Oxygen Demand, Nitrogen, Phosphorus, and Total Organic Carbons. Hazardous chemicals are those chemicals used in treating waste (such as disinfectants) and/or chemicals found in grey water introduced into a STP. Hazardous chemicals are determined by testing for residues and affects; Acidity, Alkalinity, Chlorides, pH, semi-volatiles, volatiles and other analytical methodology.

Effluent Biological testing Biological testing consists of determining the amount of natural pathogens found in human waste. These pathogens constitute harmful microorganisms that promote illness and use available oxygen thus limiting or destroying the growth of the natural aquatic system. These microorganisms are determined by testing for; Biological Oxygen Demand and Thermotolerant coliforms.

Conclusion The future of Marine Sanitation Device testing will be based on using analytical methods that will evaluate STP discharge to ensure minimum affects on the aquatic system to the point where all physical, chemical and biological elements of shipboard grey and black wastewater will be neutralized or removed. This will ensure that even in the most sensitive aquatic systems the passage of a ship will not be noticed and an earth friendly environment established.