sewage plant lime

agmantoo · #1 09/13/06, 04:36 PM

Prior to discharge, the cleaned processed water from a small town sewage treatment plant is sent through agriculture lime. The lime is frequently replaced and the removed product is available for hauling. I am considering using this spent lime to apply to my farm land/pasture to correct the acidity. Anyone know of any problems associated with this practice? TIA

**Cabin Fever** · #2 09/13/06, 06:28 PM

Wow, that's a new one on me. I have been involved in the wastewater treatment industry for 30 years and have never heard of passing treated effluent thru aglime. I wonder what the reason is? The one only things that I can think of are possibly the wastewater has an acidic pH and they are trying to bring it up to neutral prior to discharge or (2) aglime might have some ability to remove phosphorus from the wastewater.

Are you sure this isn't a lime by-product from treating drinking water? It is very common to use quick lime in the drinking water treatment process. This process results in a lime by-product that is used on farm fields all over Minnesota and other states.

If it is a wastewater treatment plant, are you sure it's not sewage sludge that is treated with quick lime or hydrated lime. This is also a very common practice that results in a product that is beneficial to soil as both a nutrient and pH amendment.

If in fact all they are doing is passing the treated effluent thru aglime, I see no reason to be concerned. In Minnesota, we have several dozen cities that irrigate the effluent directly on to ag fields and some on to golf courses. Any harmful contaminates that might be in the sewage are either degraded during the biological treatment process at the plant or they end up in the sludge. The effluent is required to meet a quality that is suitable for fishing and swimming according to the Clean Water Act of 1970.

Gideon · #3 09/13/06, 06:44 PM

A truck driving friend once dropped me a small bit on my garden site. Later I learned that it was processed sewage from Charlotte. Had a hard time eating tomatoes that year knowing where my soil treatment had come from.

**fordson major** · #4 09/13/06, 08:12 PM

there was a pulp mill that used lime in part of their treatment of the pulp and waste water. it was used with no ill effect only bennificial on acidic soils. took a special floater though as it caked ,played cane with our lines too after a farmer dumped some left over in his pit! lot of farmers still use lime from surface water treatment plants here still, it is tested for metals or contaminants as are biosoilids from the waste water plants . that which fails is landfilled

agmantoo · #5 09/13/06, 08:55 PM

The information I received was from an applicator of this product. The "lime" comes directly from the sewage treatment plant, that I am certain, and for some reason it is referred to as Stalime. The product is definitely lime colored and has the appearance of lime, I have seen it. The grind of the product is more uniform than lime I have seen however and it is wet obviously and seems to cake more than ag lime. All sludge that I have seen was dark colored, is this dark color typical? I did a google search prior to making the post, I did not read anything such as the applicator described so I made the post. Maybe I should call the sewage plant and get the info directly. I do know that no EPA paperwork or permits are needed in order to apply. The product is not hazardous either. I plan on getting 300 tons so I want to know what I am getting before getting it trucked to the farm. Sometimes things that seem so simple get overly involved in today's world.

**Cabin Fever** · #6 09/13/06, 09:21 PM

Based on your description, and the fact that no permits are needed, I would say that the product is a pastuerized sewage sludge....known in the industry as "Exceptional Quality (EQ) biosolids. This "Class A" treatment process uses quick lime to raise the pH of the by-product, the high pH together with the heat produced from the chemical reaction of quick lime and water, totally destroys all pathogens and reduces much of the odor. The product will have a fine-texture and grayish color. You can learn more about what I think you are being offered from this website: http://www.nviro.com

rambler · #7 09/13/06, 09:50 PM

If no records are needed of where you apply it, would be good enough for me. In some western states there used to be a byproduct lime that ended up having high-metal content, that was a bad deal.

Some of the sludge needs records kept of where it is placed, as well as restrictions on some crops you can grow - I'd think a little while before using those. I'm all for using rather than recycling such stuff, but the paperwork trail with your property on it for all time has some baggage.....

If they let you put it anywhere & there is no need to record what land you put it on, would be good enough for me, I'd go for it for sure.

--->Paul

agmantoo · #8 09/13/06, 10:58 PM

I read a lot at the site posted and it was very informativie. You have identified the product for certain. Here are the benefits to be derived.

One ton of N-Viro, as the product is trademarked, contains 500 pounds of calcium carbonate, 30-40 pounds of sulfur and 8-12 pounds of magnesium, in addition to 16 pounds of nitrogen and 8 pounds each of phosphorus and potash. Best estimate is that two tons of this soil amendment will equal one ton of conventional high calcium fertilizer, and in general cut use of commercial fertilizer by an average of one-third.

I was disappointed in that the calcium was less that I thought but was satisfied by the fertilizer gain. Based on the above would you venture a guess as to the dollar value of a ton of this product? Thanks for the responses!

dale · #9 09/14/06, 01:05 AM

We dont use lime in our sewer plant we filter with sand and uv lights before releasing it in to a dry creek bed.
They say it is clean enough to drink with it comes out.. But not me.

We do have sludge after the water has been treated. After an aireation process.
The sludge is then loaded on our honey wagon and taken to a local farmers field that is not used for cattle or any kind of livestock when first applied.

It is great fertilizer..

the only time we use lime is if we have the sewer plant overflow because of excessive rain. we do have some ground water inflow into our plant during high rains.
We normally catch it before it overflows and keep it in our clarifiers

dale

**fordson major** · #10 09/14/06, 01:06 AM

will be interesting too see what you get.

**Cabin Fever** · #11 09/14/06, 08:01 AM

I am so out-of-date when it comes to fertilizer prices that I could not give you a value of the product….I bettcha that Rambler could, tho.

One question to ask the people who provided you with the nutrient analysis is whether it is reported on a “dry weight” or an “as received” basis. N-Viro Soil, and similar biosolids products, can typically range from 25 to 50% moisture and still have a “dry” feel and appearance. So, when you say that the product has 500 lbs. of calcium carbonate equivalent (CCE), and if that analysis was provided on a “dry weight” basis, one ton of the actual product, as received, may have only 250 lbs. CCE (at 50% moisture content) to 375 lbs. CCE (at 25% moisture content). Of course, if the analysis provided to you was on an “as received” basis, the product would have 500 lbs. CCE per ton. In my experience, the CCE of this product is 100% available due to its fine texture. This product will raise your soil pH in just a few weeks compared to typical aglime which may take as much as a year to react in the soil due to its coarseness. Just so you’re comparing apples to apples, typical aglime has a CCE of 800 to 1200 lbs per ton.

As I alluded to before, since the use of this product requires no state approvals, it has the state and federal classification of “Exceptional Quality.” What that means is in the eyes of the state and federal environmental regulators, the product represents no threat to the soil or crops, and consequently it is unregulated. The product has no pathogens, very little to no odor, and the contaminate level is no greater than typical fertilizers or manures. The reason I know a bit about this topic is because I used to run an N-Viro Soil program in the Twin Cities.

agmantoo · #12 09/14/06, 10:02 AM

I have attempted to compare the N-viro to the current prices of lime and fertilizer in my area. I cannot do an apple to apples comparison but I may be close. The n-viro product has IMO not less than a $34 per ton value in my calculations. I will be applying at a rate of 2 tons per acre which then will give me an equivelent price of $68 worth of products per acre. My total applied costs (procurement, transport, application) are $30 per acre at that 2 ton rate. I should then recognize a $38 gain per acre above conventional ammendments. The benefits on the pastures from the n-viro as compared to conventional lime and fertilizer are yet to be determined. I am moving ahead regardless. Any thoughts?

**Cabin Fever** · #13 09/14/06, 10:40 AM

Things have come a long way since I was involved with N-Viro Soil. We used to apply a 10-ton per acre rate to harvested corn and soybean fields. The product and its application were free. We had a waiting list as long as your arm.

Since the lime in the product is so fine, it will react quickly. And because of its fineness is more effective (compared to aglime) on hayland and pastures where it is not incorporated. But here’s the rub. Because it is so fine, it doesn’t last as long as aglime. That is one reason why we applied a higher applicaiton rate. We’d get the soil pH as high as 7.5 and it would take many years before it would drop below 6.0….actually I cannot tell you how long it took before a second application was necessary…at least 10 years.

Are you applying the N-Viro for the calcium or for the liming benefit? It would seem to me that 1000 lbs/acre of lime would raise your soil pH very much.

agmantoo · #14 09/14/06, 11:34 AM

I am applying for the liming effect. The rule of thumb here is 2 tons of ag lime every 5 years. Our soils are very acidic. That is why pine trees and azeleas do so good. I think I have enough fertility tied up that improving the ph should give the same results as a good heavy application of fertilizer. Anyway, that is what I am attempting to achieve and this is cheaper. I realize that I should have soil sampled but time constraints did not permit. I will sample post application.

Chuck · #15 09/14/06, 11:42 AM

Around here they will bring it to you and spread it for free, (I signed up recently) and they have also offered to put gravel on the roads to my field and replace all my gates, just as a thank you. Even said they'd dip out my pond if I wanted.

People around here are pretty superstitious when it comes to anything from the waste treatment plant. They have a hard time getting rid of the stuff.

agmantoo · #16 09/14/06, 11:57 AM

I could have gotten some free "stuff" from another town but it came with more baggage. They even offered to kick in 2 tons of ag lime per acre. The catch was it required EPA paperwork, there was undesireable trace elements, only certain crops could be grown for a period of years and you could not graze the area for like 3 years and the applied product had to be incorporated into the soil. The product I am getting has no restrictions and is suitable to grow edibles.

rambler · #17 09/14/06, 12:24 PM

Quote:

Originally Posted by agmantoo

I am applying for the liming effect. The rule of thumb here is 2 tons of ag lime every 5 years. Our soils are very acidic. That is why pine trees and azeleas do so good.

Where I live they mine limestone. About 50% of the rocks I pick up are limestone. I've never had to lime.

Here is a web site that explains the particle size thing of ag lime. As well as CCE equivelants.

http://www.ext.vt.edu/pubs/cses/452-510/452-510.html#L2

If the lime thay are bringing in is uniformly tiny in size, it may do a lot this year, but not be around for 5 years. Tiny particles disolve right away, while bigger lumps don't disolve in 10 years. A good ag lime will have fines to mid sizes, to be effective now & through 5 years as you are used to.

You might want to watch for the roller-coaster effect if this is all real fine stuff. Typically low rates more often are needed, as you may be doing with this stuff.

I'm just guessing, not familiar with lime applications.

--->Paul