RWSA approves dredging study, modified Meadowcreek Interceptor work
By Sean Tubbs
Thursday, October 29, 2009
At their meeting on October 27, 2009, the Board of Directors of the Rivanna Water and Sewer Authority (RWSA) approved a contract for a dredging feasibility study of the South Fork Rivanna Reservoir, agreed to a modified work order for the Meadowcreek Interceptor, and directed staff to work with Schnabel Engineering on a proposal to develop a cost estimate for raising the existing dam at Ragged Mountain Reservoir by 13 feet.
Listen using player above or download the podcast: Download 20091027-RWSARWSA approves dredging feasibility study
After months of discussion between the “four boards”, the RWSA has approved a $343,778 contract with HDR Engineering to perform a series of dredging feasibility studies at the South Fork Rivanna Reservoir. The studies will provide a range of cost estimates for restoring the reservoir to its original capacity and disposing the spoils.
The full study was requested by City Council in order to determine if dredging would be a cost-effective way of providing some additional water capacity, and Council agreed to pay for studies that dealt directly with dredging for that reason. Members of the Albemarle County Service Authority did not feel the information was necessary to move the adopted water supply plan forward, and thus were unwilling to pay for the full suite of studies. Full restorative dredging, and maintenance of that condition over the 50-year period of the community water supply plan, does not by itself provide enough new water storage capacity to meet needs identified in the 2006 plan.HDR was selected as a finalist for the project in August, but the price for their services was initially much higher than City Council had expected. Earlier this month, they agreed to a “standard” study that will provide less detail. Council also removed a study that would have examined the sediment to determine if it had any “beneficial re-use.”
“We’d hate to have all that data and then not be able to express it to the public,” Fern said.Frederick said a decision on whether to conduct the beneficial reuse study anyway could be made after that meeting. HDR would hold a second public meeting when their study is complete.
One item in the study is a new bathymetric analysis of the reservoir, which will be paid for by the RWSA from its watershed fund. The RWSA will write the check to HDR and will be reimbursed by the City of Charlottesville for the portions of the study that it has requested. The ACSA will pay the $8,880 for the additional public meeting.According to City Public Works Director Judy Mueller, The City’s share of the study is nearly $256,000 and includes a pre-dredge survey, a characterization of the sediment, an analysis of dredging alternatives, an analysis of potential dewatering sites, and the final public meeting.
The RWSA’s share of the study is nearly $79,000 and includes a bathymetric study, an assessment of whether there are any federally protected wetlands in the reservoir, as well as the final report.
State regulators want answers on dam replacement
RWSA officials have been requested to appear at a November 19 meeting of the Virginia Soil and Water Conservation Board to answer questions about efforts to replace or repair the existing dam at Ragged Mountain Reservoir. A final decision about how to proceed with the dam is not expected to be made until the spring of 2010. That is when Schnabel Engineering, the firm hired to replace Gannett Fleming in designing the new dam at the reservoir, is expected to complete its work on a preliminary design and cost estimate.
The Lower Dam at the reservoir is currently operating under a conditional permit from the Department of Conservation and Recreation’s Dam Safety division. The permit expires at end of this month. Frederick said the permit might possibly be extended as long as the RWSA continues to show progress towards complying with state regulations.Frederick said that the RWSA continues to assume that the Lower Dam will be replaced by a larger one just downstream as called for in the 2006 community water supply plan. However, City Council has also directed Frederick to ask the dam’s new designers to model a scenario in which Lower Dam would be raised by 13 feet. In order to do so, Schnabel will need to perform underwater tests to investigate the strength of the bedrock on which the existing structure rests. Frederick told the RWSA Board that Schnabel’s initial guess was that it would not be cheaper to build on the existing dam because of the complications that could arise when building on 100-year-old technology.
Albemarle Supervisor Sally Thomas (Samuel Miller) asked if Schnabel would study how the Ragged Mountain Reservoir would be treated during construction. Would the pool have to be lowered, reducing the amount of water available to the community? Would the City and County have to enact mandatory usage restrictions in order to reduce demand? Frederick said he did not have those answers handy, but Schnabel’s proposal for the study will come back before the RWSA Board for a vote at the next meeting in November.
RWSA Chief Engineer Jennifer Whitaker said there are questions about the strength of the dam’s cement core. She also said to build anything on top of the existing dam, construction crews would need to remove an earthen buttress that was built around the dam in the 1930’s to address earlier safety concerns.
“There are legitimate concerns that you could not [remove the buttress] while the water was up against the dam,” Whitaker said. “You’d run the risk of tipping it over.”Whitaker said before building on top of the dam, Schnabel will need to determine how the existing dam would be incorporated into the new structure, and how the two different types of materials would bond together. She also said a higher pool of water would exert a higher pressure on the base of the dam.
During the public comment period, Richard Lloyd of the group Citizens for a Sustainable Water Plan said he thought concerns about the safety of the dam were being exaggerated.
“I don’t get it. That dam is a hundred years old. It has withstood hurricanes, it withstood Camille,” Lloyd said.Board votes to approve modified work order for Meadowcreek sewer replacement
Part of the pathway for the interceptor lies on the same right of way being used to construct the Meadowcreek Parkway. Frederick said in the initial planning for the project, it was assumed the sewer line would be laid before the roadway is built. However, due to a delay over negotiations with property owners in the City for easements to build the interceptor, the road project has moved ahead of the interceptor.At issue is 410 linear feet on City-owned land in Albemarle County where the RWSA needs an easement in order to proceed, as well as 2,130 linear feet on VDOT property. Faulconer Construction, the company building the Meadowcreek Parkway in the County, has so far delayed their work on this section of land.
Frederick suggested that the Board approve a motion to remove this portion from the rest of the interceptor project so the project as a whole can go to bid. The work on the 2,540 linear feet would be performed by Faulconer as part of their contract with VDOT. However, City Council must approve the easement on its land before the contractor can work on that section of the project. The earliest Council can take up the easements is on November 16, 2009, but they need to have two readings of the matter before it can be passed.
Thomas asked if Edwards abstention meant that she would not recommend Council approve the easements. Edwards said she would not make that decision until it came time for City Council to vote.The modified bid will be released on November 5. VDOT will be paid nearly $2 million for the work.
Other news from the meeting:
Frederick asks Board and Council to call on Richmond to appropriate an additional $175 million to the state’s Water Quality Improvement Fund. He said unless the next General Assembly comes up with the funding, the RWSA may receive only two-thirds of the state money it was expecting to upgrade the Moores Creek Wastewater Treatment plant. That means the agency may have to find an additional $3.1 million to pay for the project.TIMELINE FOR PODCAST:
- 01:00 - RWSA Chair Mike Gaffney opens meeting
- 01:30 - Executive Director's report from Tom Frederick
- 05:00 - Frederick comments on the request from DCR to update them on the dam progress
- 11:30 - Frederick says any additional requests for studies need to be made now
- 12:30 - County Executive Bob Tucker directs Frederick to submit WQIF request to TJPDC Legislative Liaison David Blount
- 13:15 - City Councilor Holly Edwards asks what information Schnabel needs
- 15:15 - Thomas asks if Schnabel's conceptual design for building on existing dam would look at different heights other than 13 feet
- 20:30 - RWSA Chief Engineer Jennifer Whitaker describes the challenges Schnabel will face
- 25:45 - Public comment from Richard Lloyd of Citizens for a Sustainable Water Plan
- 29:00 - Public comment from City Council Candidate Bob Fenwick (I)
- 31:45 - Public comment from Dede Smith of Citizens for a Sustainable Water Plan
- 35:30 - Public comment from Albemarle County resident Susan Bacik
- 37:00 - Public comment from Betty Mooney of Citizens for a Sustainable Water Plan
- 43:15 - Public comment from Liz Palmer of the Albemarle County Service Authority
- 46:45 - Dede Smith makes a correction to her comment
- 47:00 - Responses to public comment
- 50:00 - Thomas makes a comment about her role in efforts to create a sustainable water plan
- 52:00 - Edwards asks for clarification on whether bathymetric study is required and if RWSA will pay for it
- 55:20 - Edwards asks why Sugar Hollow Reservoir is down
- 59:30 - RWSA takes up engineering services contract with HDR for dredging feasibility study
- 1:11:00 - Edwards explains why Council made its decision to cut costsF
- 1:14:00 - Gary Fern of the ACSA offers to pay for second meeting
- 1:16:00 - Frederick answers question from Edwards about how studies will be paid for
- 1:19:00 - Fern makes the motion
- 1:22:00 - Frederick begins his update of the Meadowcreek Interceptor study
- 1:37:00 - Thomas reports on DEQ's new Total Maximum Daily Load requirements
- 1:39:30 - Frederick expresses his opposition to the new requirements
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