May 3, 2011
Why Not the Best? - by Jack Lynch
Recently I took a look at the NPDES wastewater permit application for the cooling tower water for the proposed 'Waste to Energy' Incinerator (WTE) in Frederick County. It is about a hundred twenty pages. And I followed through the analysis of the low quantity toxics and dissolved metals and the CORMIX model for the dilution of these elements in the Potomac River their ultimate dumping site. Read the permit yourself Here.
At first it looked quite promising, and while I'm no industrial engineer, the proposed three to one mixing of the water with the Potomac seemed like a pretty good solution, it even made it seem nearly harmless, after all, these levels of pollutants were below drinking water standards, once diluted.
Dilution is the solution is an old standard method for disposing of wastes, if you had enough water, I supposed very little would be a toxin. But we know that the bad stuff doesn't disappear, it ends up somewhere, this is the overall story of greater environmental improvements, what once seemed reasonable, now is proven bad for us and the environment.
The list of toxics was a bit scary, lead, cyanide, arsenic, chromium, copper, tin, and many others. A chart on pages 19-20 of the permit application listed them and their concentrations in the outfall. But it also held another salient fact, it shared what the possible improvement in the outfall would be if the wastewater was returned to the treatment plant.
But I had this little thought. Here we are building one the world's best wastewater treatment plants right next door to the WTE facility. Our former county waste guru Mike Marshner had said at the review of the plan that the treatment plant was so good, reverse osmosis, bioreactor membrane, enhanced biological removal (ENR) - that it would even remove most bacteria and dissolved pharmaceuticals. It was so stunningly good at it, we'd end up with such a mass of sludge filled with toxins, that no one would want to place it anywhere. Better to burn it.
OK, so this little thought, why not just return the cooling tower wastewater to the ENR treatment plant?
The chart said they'd remove 94% of the toxins if they did so.
So I had to ask, why not? I emailed my simple question, and the answer, from the Northeast Maryland Waste Disposal Authority (NMWDA)? Full text below, and I added the bold for emphasis:
"From: cskaggs@nmwda.org
Dear Mr., Lynch,
I apologize for the delay in responding to your questions regarding the NPDES permit application for the Frederick/Carroll WTE facility. I have copied your question into this email for reference and our answer is below.
QUESTION:
In reading the permit application for the wastewater discharge to the Potomac, I could not answer the question of why the cooling tower wastewater is not subsequently rerun through the WWTP, or a secondary precipitation/sedimentation system, for the dissolved metals which are its primary purpose?
I also am assuming from the materials that the reason this effulent is not discharged directly to the Monocacy is because the river flow there is insufficient for the mixing process and temperature moderation?
Answer:
Three options were considered for discharge of the cooling water blowdown; 1) return to the waste water treatment plant, 2) discharge to the Monocacy, and 3) discharge to the Potomac. The Potomac River was selected as the preferred option for discharge of cooling tower blowdown for several reasons such as, environmental improvements, engineering constraints and optimizing the use of Frederick County facilities.
The Facility will consume most self generated waste water in processes where the water is evaporated. The volume of water that will be generated by the cooling tower exceeds the Facility's ability to utilize the water in other Facility processes.
Discharge of this cooling tower blowdown is proposed to go to the Potomac via an existing, Frederick County owned discharge line through an existing Frederick County owned diffuser structure. The analysis undertaken by our contractor indicates that the quality of the cooling tower blowdown water is such that ambient water quality standards can be met with a mixing zone in the Potomac without any treatment prior to leaving our site.
The option of discharging back to the headworks of the treatment plant has been discussed and was not chosen primarily for the reason that discharge back to the treatment plant would occupy treatment capacity that has been reserved for other anticipated growth in Frederick County.
The option of discharge to the Monocacy was not preferred since the Monocacy, in the area of the proposed facility, has been designated as an impaired body of water. There is an environmental benefit to the Monocacy of removing any pollutants, even at such low amounts, which is what we propose to do by using the effluent from the waste water treatment plant in our processes and then discharging it to the Potomac.
Chris Skaggs
Deputy Director
Northeast Maryland Waste Disposal Authority
(410) 333-2730"
I was pleased to see the careful process of consideration, and I mulled upon this answer for a couple weeks and shared it with a couple folks seeking their impressions. While I immediately pulled out the logic of reserving the capacity, I had to review the numbers and settle it in my mind. After all, the permit request met and exceeded all expectations of the quality of the discharge and the modeling of the dilution approach. I am no expert, just an interested citizen informed on water issues. It was a serious debate whether it was prudent to fight the decisions and engineering and permit standards.
So I started running the numbers. Volume of wastewater - versus toxin concentrations. No treatment versus returned for treatment. It added up to an annual dumping of 32 lbs of lead and arsenic, versus a 94% reduction in the dissolved metals on the list. And the wastewater capacity of the treatment plant required? About 1.6% of the total.
I also looked at what the capacity lost could do in twenty or thirty years - at 250 gpd per home, that would be build another 1000 houses. A good tradeoff? Development that far along is a very iffy estimate in my mind, it could not happen, or the need be higher. So should it disallow the capacity use for this good? I don't think so.
Retreatment of the wastewater would be a leading example of an aggressive and progressive approach. Better yet, we were pretty unique in having an enhanced treatment facility built right next door. We would not be talking about a change of millions of dollars, just move a dump pipe back up to the treatment plant. Something already considered anyway. It seemed the right thing to do.
So there it stands. I ask Frederick County, and the NMWDE, "Why Not the Best?"
As our Board of County Commissioners said in a response to my recent commentary on WTE in the Frederick News Post, that it was the best choice environmentally and would have one of the most stringent emission control programs.
"Why not the best?"