Pray For Rain

By Steve Grimm

I find it very heartwarming to see the number of wastewater plant operators praying for rain. As the Northeast is in the midst of a devastating drought that threatens our water supplies, it’s nice to see these operators asking for Devine Intervention to ease the effects of………WHAT’S THAT? WHAT DID YOU SAY? NO! YOU MEAN TO TELL ME…..I’ve just been told these prayers are not necessarily meant to bring about the end of the drought. These supplications are being made more for a form of process control, auto wasting, if you will. I’m stunned! I can’t believe it! I…….Alright, enough already! It’s sad but it’s true. Auto wasting has become an officially unacceptable, but off the record, "what the hell else can we do?" form of process control. I know it exists. You know it exists. The regulators know it exists. Even the engineers know it exists.Are you thinking, "This sounds familiar? We’ve been here before." Well, yes it is, and yes, you have. But solids handling is an issue that bears revisiting from time to time. And besides, I told you a while ago, this is one issue I won’t give up on. I am writing this article at the end of March, and, as you know, in the springtime a young (ok middle aged) mans fancy turns to thoughts of …………solids reduction. (Boy, do I need to get a life!) It’s that time of year when we must begin to reduce our solids inventory, empty our digesters, and get ready for the summer. There’s only one problem. The sludge drying beds that were poured during the winter in anticipation of the big freeze (that never occurred) are full of mud, and they probably won’t dry out very soon. Solids will, if they haven’t already, begin to build up in the aeration tanks and clarifiers…because you can’t waste to the digesters - they’re full…because you can’t pour the drying beds -they’re full…because they’re not drying well. So, what do you do? Say a little prayer? Redundancy. What a great word. The presence of duplicate parts or systems in case one fails. Great idea. The regulators love it. EPA, DEC, and DOH all talk about redundant components and systems to assure continuous operation of our water and wastewater plants. We’ve all seen redundant chlorinators, redundant switches, even redundant primary and secondary treatment trains (often referred to as "over designed"). When was the last time you saw redundant sludge handling facilities? Or better yet, when was the last time you saw redundant sludge facilities in the design plans?Not long ago, I was asked to review the preliminary engineering plans for a small community that is under an Order on Consent to construct a wastewater collection and treatment system. The plans were nice, the site looked good, but three things caught my eye. The first was the single celled aerobic digester. I won’t elaborate on this one at this time, except to say I suggested they consider constructing two. The second was the standard uncovered sludge drying bed. I suggested that if they were not considering any form of mechanical dewatering, they should consider constructing a second bed, or at least build the one larger to handle a greater volume of sludge, if needed. The third item, which concerns future growth, is of some concern to me. There was a lot of talk of the community growing, and the possibility of industry moving in. This future growth was addressed by including future treatment units in the site plan and in the cost of the project, with one exception. The sludge handling facilities remained the same. No additional digesters. No additional sludge beds. At a product seminar not long ago, a company was explaining how easy it was to expand their system to meet the needs of a growing community. As the community grows, existing units are modified, and additional units are put on line. In the demonstration, the plant was on its third modification before there was any increase in digester size.Am I missing something here? As a community grows, doesn’t the amount of sludge that is generated also increase? If a facility needs to expand to handle increased loadings, shouldn’t the sludge handling facilities also expand? How are you going to handle the increased volume of sludge with facilities that were designed to handle a lesser amount? Pray?

There are several plants undergoing upgrades this year that are receiving additional sludge handling capabilities. These operators are ecstatic. They say, "Now we can finally get rid of this stuff, and run the plant the way it should be run". Congratulations and good luck to those operators. I’m sure it’s been a long time coming. To those who are stuck, discouraged, and left with no alternative but to watch things slowly deteriorate, pray for rain! Off the record, of course.