Mapping Failed Septic System Spillage
Created in 2024
Challenge: Design a map series for Sunapee, New London, and Newbury illustrating the predicted surface flow of septic spillage across the area.
My Approach:
- Downloaded failed septic tank data.
- Used hydrology tools like flow direction, flow accumulation, stream order, and more to evaluate the flow path from the points layer.
Results:
- Developed several maps depicting the flow path for each town at a glance and for all three at once. This analysis helps visualize how septic failures may contribute to surface water contamination.
- The points in the following images represent known failed septic system locations within the towns of Sunapee, Newbury, and New London.
- The red lines indicate the predicted overland flow paths of potential spillage, modeled using flow direction, elevation, and slope from a digital elevation model (DEM).
This supported the LSPA in reaching some of their goals regarding a source water protection grant, and was involved in Newbury’s Septic Health Ordinance Public Hearing, where they voted to adopt a new septic ordinance to safeguard public health and preserve Lake Sunapee’s water quality.