Biohaven(R) Floating Islands:
Wiconisco (PA) Wastewater Treatment Plant Tour

Submitted by:
Frederick County Watershed Management Section
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Staff members from Frederick County Division of Parks & Recreation and Frederick County Watershed Management Section observe a functioning Biohaven(R) Floating Island at Wiconisco Wastewater Treatment Plant in Pennsylvania.

This month, staff from Frederick County Division of Parks & Recreation (DPR) and Frederick County’s Watershed Management Section (WMS) joined Kevin Hedge from BlueWing Environmental Solutions & Technologies to view a new technology—BioHaven(R)  Floating Islands—at the wastewater treatment plant (WWTP) in Wiconisco, PA.

Frederick County DPR began pursuing the idea of installing a floating island after a large and potentially harmful algae bloom caused Fountain Rock Park’s quarry pond to temporarily close this past spring. To provide an immediate solution, quarry waters were treated in July with a nontoxic chemical (commonly used to treat drinking water) to oxidize the algae and toxin and eliminate any health risks.  To decrease the potential of future algae blooms DPR and WMS staff have investigated installation of a floating island—which functions like a natural wetland—to reduce nutrients, improve water clarity, and improve dissolved oxygen levels. Since excess nutrients contribute to the development of algae blooms, floating islands would serve as a defense against the blooms while also providing habitat benefits (see diagram below).

Diagram: Biohaven(R) Floating Island

Biohaven(R) Floating Islands have three basic components in their constructed base– Matrix, Foam and PVC. The Matrix consists of nonwoven fibers from recycled PET plastic drinking bottles that have been tested and found to be non-toxic to fish. The wetland plants are installed into the matrix. Foam (Coast Guard approved polyurethane, inert marine foam) provides adhesion and buoyancy. A frame of PVC pipe is inserted between two layers of matrix and cable is thread through it to connect islands to one another (http://www.bluewing-env.com/floating-islands).

Frederick County DPR and WMS staff visited Wiconisco WWTP to learn more about the islands’ performance and maintenance. The Wiconisco WWTP has three 250 sq. ft. floating islands that were installed in 2007. An additional 200 sq ft floating island that holds solar panels (to run aerators) was installed in 2009.  These islands were placed in one of the WWTP’s facultative lagoons to meet the following goals: reduce energy costs (grid-powered aeration cost $20,000 per year); reduce nutrients (nitrogen, phosphorus, and ammonia); eliminate sludge removal (cost $50,000 over 10 years); eliminate algae (cost $5,000 per year to control- not eliminate); eliminate duckweed; improve effluent clarity and water clarity; and provide more consistent dissolved oxygen. Thus far, there have been negative overall trends in ammonia, nitrogen, and phosphorus, as well as reduction in algae, duckweed, and sludge. There is very little maintenance required, and electrical savings have totaled over $18,000.

Frederick County DPR and WMS plan to collaborate to acquire grant funding to hopefully install a floating island at Fountain Rock Park’s quarry pond in the near future.