Systems Management Services  

Carmody™ Septic System Nitrogen Load & Reduction Calculator
Enter Budget Enter Total # of Septic Systems

Enter the total number of (est.) septic systems in your community and your anticipated budget.
This management tool was designed to help local governments compare costs and results of implementing septic system nitrogen reduction programs. This calculator will show you the results from three options: Septic-to-Sewer, Septic System Upgrades and Septic System Restoration Programs. We use State and Local accepted studies and research to produce a fair representation of the costs and results of implementing these programs. Copies of studies and research are available at

The calculations are based on the following:
Household Nitrogen Load: 23 lbs. per household. U.S. Environmental Protection Agency (EPA) has reported a per capita contribution of 9.012 lb.-N/yr. (EPA 1992). 2017 Census Bureau 2.54 average people per household.
Nitrogen Reduction from Properly Functioning and Sited Conventional Septic System: 50%. 2018, Wekiva-Area Septic Tank Study Division of Environmental Assessment and Restoration Florida Department of Environmental Protection.
Septic-to-Sewer: $30,000 per hookup
Septic System Upgrades: $22,500 per upgrade
Transported Waste: Based on 18 years of collected pumping records from Carmody®

Soils and underground water movement information was not used in this management tool as we found the inconsistencies in the results from the FDEP’s Nitrogen Source Inventory Loading Tool (NSILT) to be concerning, for example in the Wakulla spring area the DEP claims the 12,000-septic systems contribute 1.4 million lbs. of nitrogen a year to the springs, that is 116 lbs. N/yr. per household. That number is 93 lbs. N/yr. more than DEP has reported a household can generate (23 lbs. N/yr.). After all, with Florida’s high-water tables, ground water, canals, rivers, streams, springs, water ways, etc. that connect all our water resources makes the debate of one group of septic systems contaminating our waters more than the others seem inconsequential, as they all have the ability to affect our waters.
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