Nutrient Injection System Specialists
Of all the estuarine and coastal environments, salt marshes are the most ecologically sensitive areas impacted by oil spills. Remediation of oil-contaminated marshes is difficult with cutting and burning of marsh grass, sediment removal and replanting, and natural attenuation being common current practices. Enhanced bioremediation has emerged as one of the most effective and inexpensive methods of decontaminating groundwater and soils.
These techniques have been recently applied in the contaminated marsh in the Fore River Creek in Portland, Maine, as part of current and past Cooperative Institute for Coastal and Estuarine Environmental Technology (CICEET) projects. It has been shown that the practice of introducing nitrate amendments to the marsh substantially increases the rate of hydrocarbon degradation in the sediments by as much as 50%. The initial technique used to introduce the nitrate in past CICEET research consisted of horizontal wells, which were time consuming to install and provided only minimal marsh coverage. The present technology involves a prototype "injection system" mounted on a prototype "low impact barge" to operate at high tide in the salt marsh.
The injection system utilizes pneumatic powered syringes in conjunction with a hoisting mechanism to raise and lower the grid of syringes to the marsh surface below the water line. The pneumatic and mechanical systems are controlled through the use of a programmable logic controller, which allows the injection system to be automated. The prototype injection system was built at a cost of $1900 and is ready for testing in the marsh environment.
Available from the National Sea Grant Library (use NHU number to search) or NH Sea Grant
- Nutrient injection system specialists (NISS) (2002). Richard Clark, Matt Levander, Glenn McGillicuddy, James Mulcahy and James Tyler. Advisors: David Fredriksson, Nancy Kinner and Tom Ballestero.