Denitrifying Onsite Septic Systems

Denitrify:  To remove nitrogen or nitrogen groups from a compound.

It is surprising to me that so many newspaper stories are written about denitrification.  I see these articles every day and, considering that denitrification in onsite septic systems seems to be such a popular topic, I am equally surprised at the lack of knowledge regarding them.

I see (and hear) all kinds of goofy statements about onsite systems and their ability to remove nitrogen. For example, when a leader in the field of onsite systems makes the statement that excellent nitrogen removal results are only possible if the occupants of the home are wearing diapers.....well, it's pretty clear to me that there is a problem in this industry.

The subject is complicated by the fact that many health department regulators don't really understand these systems and have to rely on manufacturers representations.  Obviously, manufacturers exist to sell treatment systems and there are a couple of ways they can do this:

1) Sell a good product at a fair price that produces the required results.

2) Emphasize expensive marketing, government lobbyists and misinformation.

To be sure, there is never a shortage of number two in this industry.

For instance, I was reading comments from a newspaper article in Rhode Island where denitrification systems have become a regularly discussed topic.  These readers were quite concerned that they would have to spend somewhere between $30,000 to $50,000 to install a denitrifying septic system for their home.  I would have been shocked by this dollar amount if I had not had similar experiences with the cost I have seen charged for these systems. 

If you need a denitrification system for you home or business, I can almost certainly help you get a better price.  Just mention the name, "Eliminite" to the person giving you the quote for Brand X.  Ask them about the nitrogen removal numbers from their systems and have them compare Brand X's numbers to Eliminite's numbers.  (I've included some recent sample results below)

At this point you should see some concern in their eyes and body language.  Most will try to tell you they have never hear of us and, because they are such experts in the field, and have been doing this work for 30 years, that if they have never heard of Eliminite, well, you shouldn't even consider a system they have never heard of.  But, if you press them a little, I have seen the Brand X's drop their price by 20%, 30%, 50%  in one step because they know two very important facts about Eliminite.

1) Our nitrogen removal numbers are far superior to theirs, and;
2) The cost of an Eliminite system is generally half (1/2) the cost they are going to quote to you.

Now you can imagine, these two facts can be quite disconcerting to suppliers of competing systems.  A common tactic is to try to talk over your head; tell you about BOD, COD and nitrogen ratios, give you a quick and dirty water chemistry lesson on pH and acid-base reactions.  They will tell you that you have to feed a septic dog food to get really good nitrogen removal numbers, or that you need to add sawdust, or wood chips, or upflow reactors or, that you need to wear diapers.  (I am not making this up!)

My advice is generally to trust your intuition.  If something does not sound quite right, or if you think you may be on the receiving end of a well crafted script, don't immediately think you are wrong.  If something sounds screwy (you have to feed a septic system dog food, for instance) it probably is wrong and you probably are right.

Here are some results I recently received from several Eliminite denitrification systems. The systems were installed by independent septic system contractors.  I was not onsite for any of the installations.  The samples were collected by a third party certified maintenance provider that services many other systems.  I had no role in collection or review of the samples other than to receive reports from the lab that conducted the analysis.

System 1) TN = 12.9 mg/L
System 2) TN= 6.4 mg/L
System 3) TN= 1.71 mg/L
System 4) TN =19.0 mg/L
System 5) Ammonia + Nitrate =2.3 mg/L
System 6) Ammonia + Nitrate =3.2 mg/L
System 7) TN =7.7 mg/L
System 8) Ammonia + Nitrate =9.9 mg/L

Average of  all eight: 7.9 mg/L

It is obvious that System 4 needs an adjustment.  It would take about 5 minutes to make this adjustment and I would expect its numbers to drop into the 5- 6 mg/L range.   These are real denitrification systems operating at real homes. 

Samples were also recently collected from a subdivision in Montana with about 20 individual Eliminite denitrification systems.  The subdivision is configured with individual treatment systems discharging to a central drainfield.   The Eliminite units discharge to a central dose tank and the certified O&M provider collects a sample from the dose tank.  It is interesting to see the nitrogen numbers change as new homes are added to the system.  The last winter sample was TN= 11 mg/L.  Three new homes were added this spring and the spring sample was TN=13mg/L.  As the three new systems develop, the nitrogen numbers will come down again.  BOD for the two were like 4 and 5 mg/L. 

These numbers represent about an 85% reduction in Nitrogen and about a 98% reduction in BOD and we do it with only one additional tank.  A normal residential system consists of one primary (septic) tank and one Eliminite tank. Every number above is from that simple configuration. 

I want to tell you the price but, as you may imagine, I am reluctant to include it on this blog.  I am confident that we have about the best prices in the industry by a fairly wide margin.  In general, all the same system brands are available in Montana that are available in your state and we were not always the most popular advanced treatment system.  But, over the last few years it has become apparent that people are more cautious with their money and spend a little extra time shopping for the best value.   They do their homework and ask about the cost of state-required maintenance, energy costs, treatment results and visual impact of the system.  In this cost-analysis, as with the lab analysis, Eliminite comes out on top with most people who need an onsite denitrification system.