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Test results - Long-Term Composting

The end-product from the CompostEra-process consists primarily of a "compost tea" which has been stabilized during the passage through the filter bed in the bottom of the process chamber. This liquid contains the main plant nutrients (N,P,K) but also mikro-nutrients taken out of the soil at the harvesting. The mikro-nutrients are the source of taste and nutrition and by repeatedly using chemical fertilizer we impoverish the soils and create a low-grade food. This is a serious down-ward spiral affecting everything from hay to fruit and vegetables.

The solids from fecal matter and cellulose shall be left in the process tank as long as is practically possible (as long as there is space available for new waste in the tank). An almost full tank functions best and can stay at this level for many years.

In the table below, a variety of test data has been assembled from several decades of operation.

Table 1 End-product from a multrum, Fecal coli bacteria.

Samples from Clivus typ Install. yr Visits/yr Lab/Date Fec. Coli
Nevada Highw,Dept. Large Tank 1982 34000 (1) 1983 7
Wildlife Prairie Park Large Tank 1978 14000 (2) 1981 <2
Hushåll i Pennsylv. Smaller Tank 1976 7000 (3) 1981 35
Sverige, 7 tankar* Large Tank Before 1972 Irregular use (4) 1976 Not detected
Sverige, 7 tankar Large Tank Before 1972 Normal use (5) 1972-75 Not detected
NSF's Standard <200
Septic tank Bench-mark. 100,000
(1) Sierra Environmental Monitoring Inc., Rena, Nevada
(2) Microbe One, Ann Arbor, Michigan
(3) National Sanitation Foundation, Ann Arbor, Michigan
(4) Center for the Biology of Natural Systems, Wash. University, St Louis, Missoury

*This test was performed by CBNS, Washington University, St Louis MO An extensive investigation summarized below.

Table II Compost-tea

Location Yr inst. Visits/yr Lab /yr Fecal Coli Lab/yr N(tot) g/l Type
Wildlife Park, IL -78 14,000 (1) -79 0 (3) -82 9.4 g/l Large
Shelly Ridge, PA -80 6,000 (2) -81 2 - - Medium
Camp Archb., PA -80 8,000 (3) -81 0 (3) -82 2.7 g/l Medium
Hawk Mtn, PA -76 20,000 (4) -82 6 (4) -82 6 g/l M (2 tanks)
Kain Park, PA -79 14,000 (4) -82 43 (4) -82 5.5 g/l Medium
Blanford Cent .,MI -81 14,000 - - (3) -82 3.2 g/l Small
Residential, MI -78 3,000 (6) -80 3 - - Small
Residential, MI -73 6,000 (5) -74 0 (5) -74 7.4 g/l Medium
EPA stand swimm <200/100ml
Septic Tank Effluent Normal Typical 430,000
(1) Peoria Illinois,County Health Department
(2) Quality Control Laboratory, Southhampton, PA
(3) Seewald Laboratories, Williamsport, PA
(4) Alchemis, Inc. Bath, PA
(5) Process Research, Inc. Cambridge, MA
(6) Microbe One, Ann Arbor, MI

Analysis from "liquid collection tank"

(Tank for the stabilized liquid originating as urine) from one of the swedish highway administration's rest area on the E6 outside Falkenberg. (officiell data)

Date of sample 980420
Arriving the lab. SMI 980421
Sample taken by Ulf Hedin
SMI #:
S44 Inomhustank, Susedalen East side
S45 Inomhustank, Susedalen West side

Samples taken from two collection tanks for the stabilized end product from the compost tanks, originally from urine after passing the bio-filter.

Samples taken from two distinctly different systems (one on the west side S45 and the other S44 from the east side of the E6 highway)

Parametrar S44 S45
pH 8,60 9,09
Coliform bakt./mL <10 <10
Thermostable ckoliform/mL <10 <10
E Coli/mL <10 <10
Fecal Strep. /mL <10 <10
Sulfit reducing clostridier /mL 30 1
The low concentration of indicator organisms show the absence of fecal presence and that the treatment process has worked. There is a small presence of Clostridium which may not have fecal origin.

Vatten och Miljölab, 980424
Provtagare Carl Lindstrom

[signed TAS/Görel Allerstam]

Thor Axel Stenström / Görel Allestam
Chefmikrobiolog, PhD / Biomedicinsk analytiker

Table III Ventilation exhaust gases at the vent. exit

Gas in Clivus vent gas Fed. Air Quality Stand. NIOSH* workroom lim.
CO2 0.2% None (ambient is 0.04%) 0.5% safety limit
Water vapor Å95% relative humidity - -
CO none detected (<8 ppm) 9 ppm 50 ppm
SO2 none detected (< 1 ppm) 0.03 ppm 5 ppm
hydrogen sulfide 0.5 ppm - 10 ppm
ammonia 3 ppm - 25 ppm
methyl mercaptan (bad odor) none detected(<2.5 ppm) - -
methane gas (explosiv above 10,000) 4 ppm - ambient (0-4 ppm)
*NIOSH is short for the National Institute of Occupational Safety and Health.

Based on 45 years experience


Carl Lindström is a civ. egineer from KTH Stockholm and MIT Cambridge MA. He is the co-founder along with his parents of the first commercial composting toilet Clivus AB, which later became Clivus Multrum AB. There was an early assumtion that the system would produce solid compost. Over the years a new process has emerged called Long-Term Composting (see video on the left) where the end-product is liquid and the solids is left for several decades. Based on decades of observations, a next generation process-tanks have been developed, taking less space and working with less maintenance and service than the older Clivus tanks. Carl was in the 1970ies working for the Swedish Environ-mental Protection Board and later served as environmental attché in Wash. DC. He works now as earlier with the US corporation Clivus Multrum USA Inc. In 2007 Carl founded CompostEra AB in Sweden with sights set on solving waste problems in the Swedish archipelago, replacing the older latrine-collection systems. The new tanks are dimensioned to go for 30-50 years without solids-removal.

Long-Term Composting has found great support in countries where ground water is vulnerable to pollution from toilet-systems that do not stop disease organisms from spreading into the environent.

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