Design and Testing of a Water Sampler for an Autonomous Underwater Zip-Line Robot

Shellfish aquaculture is a critical industry in many coastal areas, but when located near high population densities, it can face significant challenges due to sewage overflows during heavy rainfall. Each significant combined sewer overflow (CSO) discharge not only impacts general water quality, but also temporarily closes shellfish beds. Addressing these challenges requires improving the frequency and accuracy of water quality and CSO discharge measurements, ensuring that shellfish beds are only closed when necessary. To support this goal, we designed a multi-container water sampling system integrated with a pre-existing autonomous underwater zip-line robot [1]–[3]. Our water sampler is designed to collect five unique water samples during a single deployment, offering the ability to get an accurate picture of the water quality across different depths and locations. These samples are collected using solenoid pumps and valves, a two-part fluidic manifold/electronics housing end cap, an array of syringes, and an electronic housing. With the implementation of our water sampling system, water quality can be regularly measured across a wide area, ensuring that beds can be reopened as soon as water quality reaches a safe level. Since the water sampling system can easily be swapped, emptied, and maintained, water samples can be taken very often, allowing analysts to confirm the correctness of water quality measurements before reopening shellfish beds, maximizing the operational days of aquaculture producers. In this paper, we discuss the design, fabrication and preliminary testing of our sampling system, along with suggested future changes and improvements based on testing results and constituent feedback.