Algae Removal System Helps Clean Up Ontario Beach

The shoreline of Ontario Beach in Rochester, N.Y., has an ongoing problem with algae accumulations of cladophora, a type of light-dependent, green nuisance algae which grows on the hard bottom surface of the lake and is carried to the shoreline by currents.

Ontario Beach, a recreational bathing beach at Ontario Beach Park in New York, is located on the southern shore of Lake Ontario, near the mouth of the Genesee River and bounded to the east by a U.S. Army Corps of Engineers (USACE) navigational pier. The beach and pier are popular spots for pedestrians, bicyclists, and beachgoers and are operated by the Monroe County Parks Department.   

At Ontario Beach, algae accumulate where the eastern end of the beach meets the pier. These algae accumulations decay and generate odors, degrade water quality and collect debris. Excessive algae can lead to closures of the swimming beach during the summer months because the algal masses look and smell horrible. They also provide a substrate for bacterial growth. As a result, Monroe County and the City of Rochester have long desired a procedure for gathering and moving the algae out of the beach area.

In the late 1970s and 1980s, Monroe County managed algae by pushing the accumulations to the shoreline with a front-end loader and returning after some dewatering had occurred to rake and remove the material. This approach was labor-intensive and did not adequately address the aesthetic and odor issues caused by the algal masses.

In 2001, 2002, and 2007, USACE funded field studies performed by URS Corp. to evaluate a number of operational gathering, pumping, and disposal measures for algae control. More than 30 options were evaluated, including screening and dewatering, artificial circulation of stagnant beach waters, treatment of algae-laden waters, modifications to the beach configuration, offsite composting, landfill disposal, and various onshore handling methods. The top alternatives were deemed to be too capital-intensive (at up to $7.3 million in construction costs), impracticable, or undesirable to address the problem. As a result, none of the options were implemented.

A simpler and less capital-intensive solution was desired. The concept of an algae-herding operation paired with a portable algae pumping system was conceived by the county, and in 2011, USACE provided project funding and assembled a project team of the Monroe County departments of Health, Parks, and Environmental Services, the City of Rochester, and URS to test the concept.

With permitting coordination from USACE, the New York State Department of Environmental Conservation (NYSDEC), and the U.S. Fish and Wildlife Service (USFWS), URS developed a procedure and work plan tested in a field demonstration during the summer of 2011.

The proposed algae removal system concept plan. Credit: URS

The system consisted of a plan to herd waterborne algae with a bucket loader toward the pier. A movable suction intake was deployed in the near-shore area near the west pier using a long-reach backhoe. The suction head design was a key component of the system, as it needed to operate in shallow water (up to 8 inches deep) and minimize sand entrainment, eliminate air entrainment, and not harm fish. Piping was set up across the pier and a portable pump was used to discharge the collected algae (at rates from 1,000-2,000 gallons per minute) over the pier, where it was discharged into the lake side of the Genesee River using a submerged diffuser.

Sampling and monitoring activities were performed throughout the course of the month-long study, including wind and weather conditions, Genesee River flow conditions, visual observations of the discharge point, analytical sampling at points upstream and downstream of the discharge point, and visual monitoring of adjacent beaches along the Lake Ontario shoreline.


Algae herding during the July 2011 field demonstration. Credit: URS

The field demonstration was largely deemed a success. Several significant “algae events” were managed and removed by the system. Light to moderate algae events were typically removed from the beach in 30 minutes to five hours. The system was able to achieve visual improvements and reduce algal odors during all pumping events. A “very heavy” algae event that occurred during the course of the demonstration was managed by the algae removal system within 2.5 workdays, an event that would normally result in up to two weeks of beach closures, according to the Monroe County officials.

A “very heavy” algae event during the 2011 field demonstration, before pumping. Credit: URS

The algae removal system was not observed to have any significant effect on the water quality of the Genesee River downstream of the discharge point.  It was observed that the algae plume dispersed quickly in the river and for the majority of the pumping events, the algae plume could not be seen from the pier. The USFWS performed monitoring and testing for a portion of the study and indicated that they did not anticipate significant impacts to fish and wildlife as a result of the system.

Ontario Beach following clean up of the “very heavy” algae event. Credit: Monroe County Department of Environmental Services (DES)

As a result of the success of the demonstration project, a full-scale implementation of the algae removal system was recommended. In 2012, Monroe County secured funding for the project through an NYSDEC grant. Coordination with other agencies included U.S. Coast Guard, Rochester Comprehensive Planning Group, New York State Historic Preservation Office and the New York State Department of State.

Construction of the permanent algae removal system was completed in August 2014. The total construction cost of the system, including procurement of herding equipment, was $400,000. The project established a permanent pipe through the west pier, and the permanent installation of a discharge pipe and two diffusers in the lake. The remainder of the system consists of a portable pump, suction hose and suction head. The Monroe County departments of Parks and Environmental Services will mobilize the equipment and operate it seasonally. The system is scheduled to be placed into operation in the summer of 2015.

Although mitigating the problem through mechanical intervention is not a permanent solution to a water chemical composition problem, it should help to minimize the beach closure problem at Ontario Beach. Long-term solutions to address the source problem are still required.

Construction of a permanent algae removal system. Credit: CP Ward Inc.