Brian Romeiser began composting biosolids more than 20 years ago at the Manchester-Shortsville (N.Y.) Joint Sewer District, where he is chief operator. He made the move mainly for cost reasons — landfilling was getting too expensive.
But now, he sees another compelling reason to consider composting: The public readily accepts the end product. In his experience, the concerns residents raise about beneficial use programs involving biosolids disappear when the material is mixed with bulking agents and turned into a product suitable for use on lawns and flower gardens.
Romeiser came on board at Manchester-Shortsville in 1984. He now operates a 0.88 mgd facility with secondary aeration and contact stabilization. He holds a 3A wastewater treatment license and a 2A water treatment license for New York and owns an associate degree in construction technology from Alfred Agricultural and Technical School in Alfred, N.Y.
Since he started composting at his own facility, he has helped other wastewater treatment plants devise their own composting systems. Since 1990, under the umbrella of L.B.E. Consulting, he has consulted in the design of 13 composting facilities, of which nine are in operation today. All meet federal and state regulations, and none have had start-up issues related to design. Romeiser talked about his experience with composting in an interview with Treatment Plant Operator.
TPO:
How did you decide to adopt composting at your facility?
Romeiser:
In 1985, we were hauling solids to landfill at a cost of $7 a truckload for the tipping fee. In 1986, the tipping fee increased to $36 a truckload. I decided there must be a better way.
I went to the state Department of Environmental Conservation and talked to Sally Rollins, who was in charge of all solid waste and still is today. When I told her I was interested in composting, she advised me to look to Denver, as they were composting at the time. I got on the phone with them, they gave me some information, and in 1987 I proceeded to experiment.
I got a permit for composting in 1988, and I have composted everything since then. We started with aerated static pile composting, and it really hasn’t changed, although we’ve improved it here and there.
TPO:
How does your overall biosolids process work?
Romeiser:
Ours is a small package plant with aerobic digestion that produces a very well digested sludge. We typically run 60 to 70 dry tons per year, or in wet tons, 10 per week. It comes off a belt press at about 12 percent solids because we have one of the earlier-generation belt presses. We mix it with wood chips that a local tree surgeon delivers to our site for free.
We mix it, compost it for 21 days, and put it into a curing pile for 30 days. Sometime during that 30-day period, we sift it to remove the larger pieces of bulking agent. In New York, there is a rule that says to meet Class A compost standards, the material must pass through a 3/8-inch screen and meet the metals limits.
When you sift compost, especially aerated static pile compost, you get approximately 75 to 80 percent of your bulking agent right back to use in your next pile. So we need very little bulking agent per year.
TPO:
What do you do with the compost?
Romeiser:
The compost is pretty much used in two ways. It’s all a giveaway program. The residents have first chance at the compost in a first-come, first-served program. We start about May 1, and within one month they’ll have cleaned out our winter supply. Then, as we make the piles through the summer and get them ready, more residents come and pick it up.
Around September, the residents have had all the compost they need, and I start stockpiling. Then a local school district comes and takes the compost for the ball fields. They take all I can make. They would take everything I make all year long if I let them.
It’s quite easy to get rid of, and I don’t have to truck it. I don’t truck final compost out, I don’t bring raw wood chips in, I don’t do any trucking. The only costs I have involved are my time in making the compost and a little electricity for running a blower.
TPO:
What do your composting facilities look like?
Romeiser:
I compost everything in a fiberglass pole barn, 16,000 square feet. We do all the composting, all the wood chip storage, everything inside that building. We do everything inside because then we have control over the environment.
In 1987, I purchased all the composting equipment: the mixer, the sifter, the blower. I paid for the whole works in two years with savings from biosolids hauling. From then on it’s been just the cost of O&M to keep the facility going. I’ve saved thousands and thousands of dollars. It used to cost me in the neighborhood of $50,000 a year to haul the material to the landfill. I’m looking at an O&M cost right now of about $6,000 a year.
TPO:
What exactly is aerated static pile composting?
Romeiser:
You start with a pipe at the base of the pile — I prefer to use 6-inch ABS field drainage pipe. You put wood chips over that pipe, and then put your initial compost mixture over the top of that to anywhere from 8 to 10 feet tall, and no more than 12 to 14 feet wide. Then you cover the pile with wood chips about one foot thick.
You hook a blower to the end of the pipe to feed oxygen to the bacteria, and insert a temperature probe into the pile near the front end, within a foot and a half of the pipe. That will sense the coldest part of the pile and will activate the blower.
When the temperature reaches 57 degrees C, the blower kicks on and blows air into the pipe to cool the pile down. When the temperature hits 55 degrees C, the blower turns off. We usually run three piles, some-times four. If we have to press more sludge, we just add another pile.
TPO:
What’s the key to preparing high-quality compost?
Romeiser:
The big issue in composting is getting a uniform starting mixture with between 38 and 42 percent solids. It needs to fall within that range, period. If it doesn’t, you will not get your pile temperatures up to what you need, which means your piles will fail. You also have to keep the mixture uniform as it goes through its process. If you get a lot of rain and snow on the mixture, it will not do well.
We cover our piles with a foot of wood chips as an insulating blanket. The biosolids in mixture with the carbon content of the wood chips sets up conditions in which the bacteria will work and build up temperature all by themselves. We take the temperature twice a day for 21 days. For three consecutive days it has to be higher than 55 degrees C, and for the next 11 days it has to be above an average of 45 degrees C, by state regulations.
TPO:
Is there a secret to getting the starting mixture right?
Romeiser:
When I train a plant to start up in composting I explain to them what they need to mix. I convert everything to simple bucket mixture ratios — 2:1, or 2.5:1, something they can understand. Then, for the first half-year, I have them do percent solids testing in their lab. By then they have a pretty good idea what mixture they need on a daily basis, and they no longer do much solids testing.
Most every treatment plant’s sludge is consistent. Once you get used to your sludge and know what the numbers are, the only thing that really changes is the wood chips. The wood chips can vary drastically in percent solids, depending on where you get them and how much rain is on them. If you store the wood chips inside, they get very stable, and very shortly you know the numbers. If you store them outside, you need to do the math often, because you will see a wide variance in percent moisture.
TPO:
Under what circumstances would you recommend that a plant consider composting?
Romeiser:
Plants usually look at composting because they’ve had problems in solids handling. They’ve had problems getting rid of biosolids, problems with residents in land spreading, or problems with landfills. Once you exceed $60 a ton to handle biosolids, you’re approaching the point where it’s a monetary advantage to compost.
TPO:
In your observation, what’s the difference in public perception between biosolids and compost?
Romeiser:
The public perceives sludge as a very bad thing. They perceive compost as a very good thing. In this day and age of recycling, organic compost fits the bill perfectly. On top of that, whereas normally if you buy anything organic you pay more for it, they get this organic compost for nothing.
At first they come and take a 5-gallon pail or bag of compost home and put it on their flower garden or their lawn. Within six weeks they’re back for a whole truckload, and they become a yearly user of a truckload or more. People love it. Usually, by about the third trip back, they want a tour, so I give them a tour of the whole plant. This gives me a chance to educate the public on our operations.
When it gets to about the first of June and I only have one pickup truckload left, people show up at 6 a.m. and they fight over that last truckload. It’s simply amazing. I have never found a plant that can’t get rid of its compost. Whether they sell it or run a giveaway program, they always have places to go with it, and it never costs them anything to get rid of it.
TPO:
What advice would you have for treatment plants that plan to switch to composting?
Romeiser:
I try to convince them that if they’re going to get permitted for aerated static pile composting, they should get permitted for windrow pile composting at the same time, because it doesn’t cost you a dollar more to get double permitted.
If you do that, and you have an equipment failure, you can easily turn an aerated static compost pile into a windrow pile if you’re permitted for it. You don’t have to keep a lot of spare parts for the static pile operation lying around the plant. You can just turn that static pile into a windrow pile and order your parts.
TPO:
How does windrow pile composting work?
Romeiser:
With a windrow pile, you take a loader and stir the pile five times in 15 days out of the 30 days and read the pile temperature with a portable probe. By doing that, you eliminate the blower. You create more manual labor by having to stir the pile, but you don’t have to worry about the blower.
TPO:
How does compost production vary with the seasons? Is cold climate a disadvantage?
Romeiser:
You can compost in wintertime, but you have to understand that if you’re using frozen material, if your wood chips are very cold and your mixture ends up below 4 or 5 degrees C, there’s a good chance your pile will not start without help.
We have a procedure that seems to work very well. We take a kerosene heater, point it at the intake of the blower, and turn the air on into the pile after we’ve mixed the pile for about four hours. In a very short time, the pile is up to a temperature where the bacteria can start working, and you just turn the heater off and walk away.
TPO:
Is composting a technique that’s limited to small plants?
Romeiser:
Not at all. The City of Denver composts. The City of Philadelphia composts. New York City is composting now. Small plants in general can only do two kinds of composting — windrow or aerated static pile. They can’t do in-vessel composting because it’s cost-prohibitive. You have to exceed about 5 mgd before you can justify in-vessel composting.
TPO:
How would you assess the future of composting in the United States?
Romeiser:
If you have a facility that can meet the Class A limits with heavy metals, I think composting is an absolutely great way to go. It meets the recycling attitude that prevails in the United States and the world. It is a pretty easy recycling method, and the material you produce goes right back on the local sites.
I believe in composting tremendously, because for 20 years I’ve seen it work in quite a few treatment plants. They all seem to be doing extremely well, pretty much with no issues. When you have that kind of track record, it’s pretty straightforward.
