Agenda - 12-07-2015 - 6-a - Minutes

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21 1 For many years hydrilla has been present in portions of the Eno watershed, including 2 Lake Orange, Corporation Lake, and the West Fork of the Eno Reservoir. More recently, Eno 3 River State Park staff noted that hydrilla is their "number one resource management problem in 4 the Eno". Hydrilla causes negative water quality impacts, can be harmful to the river ecosystem, 5 and adversely impacts the recreational experiences of people visiting the State Park and 6 elsewhere. Hydrilla can be spread from one water body to another via watercraft or waterfowl. 7 The plant can also be spread by people discarding aquarium materials into waterways. 8 In 2011 the Eno River Hydrilla Management Task Force, comprised of local 9 governments and state agencies, including the Aquatic Weed Program of the NC Division of 10 Water Resources, began planning to address the hydrilla infestation in the Eno River. The Task 11 Force agreed to conduct a two-year pilot study to examine the effectiveness of using a US 12 Environmental Protection Agency-approved herbicide to manage hydrilla in a portion of the 13 river. In April 2015 the Task Force hosted a public information open house in Hillsborough 14 concerning the pilot study (Attachment B). Details were provided on the problem, the results of 15 an Environmental Assessment for the proposed project, and the selection of a contractor to 16 apply and monitor the herbicide in the Eno. Additional public outreach efforts were conducted 17 throughout the watershed (Attachment C). 18 Pilot study herbicide treatments in the Eno River began in late May 2015. Low stream 19 flows over the summer aided in maintaining a consistent concentration of fluridone, the active 20 ingredient in the herbicide, throughout the treatment zone, from Lawrence Road east of 21 Hillsborough downstream to Roxboro Road in Durham. Monitoring of the concentration of 22 fluridone in various locations along the river occurred throughout the duration of the study. 23 Monitoring of native vegetation, snails, crayfish and fish above and within the treatment zone 24 was also conducted before and during the hydrilla treatment. Bleaching of hydrilla was 25 observed after just one week of herbicide treatments. Within four weeks, there was notable 26 reduction in the density of hydrilla in the treatment zone. Further herbicide treatment resulted in 27 dramatic differences in hydrilla density between the treatment area and the untreated area 28 upstream. Nearly-complete removal of visible hydrilla vegetation was reported at locations 29 within the area of treatment. 30 The Eno Hydrilla Management Task Force will continue to evaluate data from surveys of 31 the Eno River ecosystem both within and above the treatment zone. Native vegetation is 32 responding positively. It is anticipated that the results of the first year of the pilot study will be 33 overwhelmingly positive, and that the Task Force will proceed with the second year of 34 treatment. Over the winter months, the Task Force will consider using a lower concentration of 35 fluridone, starting the injection process earlier in the growing season, and adding a second 36 injection location in order to further minimize the apparent impact to native plants. Following 37 completion of the full two-year pilot study, the Task Force will begin to discuss long-term 38 objectives for the management of hydrilla throughout the Eno River watershed. 39 Lastly, the County recently completed a contract with the NC Division of Water 40 Resources for the addition of sterile grass carp to Lake Orange, which is infested with hydrilla. 41 Grass carp are routinely used to help control hydrilla in lakes and reservoirs. 42 Chair McKee said all information should be put out to the public as soon as it comes in. 43 Commissioner Jacobs said the expected effect of the fluridone on the natural 44 environment was not specifically known. 45 Tom Davis said toxicologists were consulted before the treatment started. He said the 46 treatment zone was picked because it was below the water system in Hillsborough. 47 48 Bonnie Hammersley said this is the last work session of 2015. She said she, Travis 49 Myren, and Chief Financial Officer Gary Donaldson started working on the 2016-2017 budget