Editor’s note: This is an email sent from Key Biscayne Village Manager Andrea Agha to Council members and shared with Islander News.
Good morning Mayor and Councilmembers,
On Wednesday, October 2, I was informed by (the Water and Sewer Department) staff that a request from the Village Council had been made to (Miami-Dade County Commissioner Xavier Suarez) for a representative from WASD to attend our October 15 regular council meeting. Village administration has a strong working relationship with County staff. After reflecting on all the open items we are collaborating with on WASD, we would recommend their participation in our workshop, where we can dedicate the time and energy to a thoughtful and productive workshop as opposed to an unplanned Q&A of County staff in a public setting. I have only received positive feedback from Council on the workshop so we will begin planning (for) that.
Notwithstanding, we sense the most pressing question is with regard to whether or not the sewage system on Key Biscayne is in any way related to the beach closings. I would like to provide a brief summary of the situation and what our plan is moving forward to help Council respond to questions you may be receiving.
We have been advised by WASD leadership, through their collection system staff that most of the old part of the Village’s collection system was installed between 1965 and 1981, and most of it is vitrified clay pipe, which was the preferred pipe material at the time due to its resistance to corrosion. WASD has 3 "smart manhole covers" that measure levels in the system in real time so that they can react if levels are rising and threatening an overflow. Those have been in place for 1 to 2 years, and they have recorded no overflows in the past year. In February WASD added two more of the smart covers to better understand tidal influences on the collection system. There have been no overflows at those locations, and no indications of levels in the system indicating excessive infiltration of groundwater. We are pending requested maps and records they have regarding televising of the collection system to determine the extent to which leaks are allowing ground water to infiltrate into the lines or the reverse, sewage in to the ground water. We will provide an update when we have that additional information.
WASD has also been monitoring conditions both at the treatment plant and in the collection system because of the concern about beach conditions, and they have yet to find evidence that would tie the operation of the wastewater system to the frequency of beach closings. Waste water could exfiltrate into ground water and be tidally moved out toward beaches; this is one reason we are monitoring groundwater levels compared to the elevation of sewer lines. Most recently it seems apparent that the extreme tides have had an impact in terms of street flooding that eventually finds its way back to the bay.
In addition to the work we are doing with WASD, the Village is also working with the University of Miami on the bacterial source testing. We will be providing an update on that research as it becomes available. At this point, our understanding is that there is no indication from UM’s research that definitely ties the water quality issues to WASD infrastructure, but the research is still in process.
As tired as perhaps we all may be for the need for more data, we certainly think it is important to have reliable data as the basis for making significant investments so that there is an assurance of a return on the investment. To that end, our next step with WASD is a method of evaluating any failures in the system that would allow for waste water to contaminate ground water by a process called televising. Televising of systems is routinely done by WASD with their own equipment. We are working collaboratively with WASD staff on a proposed sampling of the Village’s older WASD infrastructure. We will be using data we already have to identify what may be the more likely points of failure based on past experience. It would be helpful to us if there are specific locations that residents have concerns about either by way of professionally documented failures or observation, and I would encourage you to please let me know of any particular instances that you are aware of.
WASD operations staff will do the initial televising for determination of exfiltration of sewer system waste to ground water over the next several weeks. We hope to report preliminary findings at the resilience workshop where WASD staff can present their findings alongside the other experts the Village is working with.
Finally, I will point out we are also coordinating with WASD on our stormwater improvements to provide for less disruption to residents, economies of scale and cost savings to do any WASD work while the Village has the roadways open.
Hope this helps. Please let me know when there are questions of County staff so that I may serve as your conduit to the professionals who can best assist us.
Please let me know if there are additional questions or concerns.