Urine Diversion System for
Barrel Composting Toilet
(Updated 4-12-13)

 

The urine diversion option requires less maintenance than urinating into a bucket, which requires daily emptying of urine into a mulch basin.  The urine diversion option consists of 3 basic assemblies: a urine diverter built into each barrel, a subsurface leaching chamber and an optional urinal for men.  Perennial plant roots near the leaching chamber can uptake water and nitrogen in the urine. 

The urine diversion option is described in the photos below.  Also see materials list at bottom of page.

Urine diverter in barrel toilet. 

Stainless steel screen to prevent urine drain from clogging.  Urine drain is made from Super Quick Fill Funnel and secured to barrel with two #10 x 2" stainless steel machine screws and nuts. 

 

 

 

Urine diverter secured to front of barrel with stainless steel machine screws.  Note urine drain hose at bottom of funnel.

Urine diverter construction begins with drilling 1/2" hole vertically through rubber stopper.  During frilling, grip stopper gently but firmly with pliers.

 

Pass hose through funnel, then slide stopper onto hose until end of hose is flush with top of stopper. 

Urine diverter ready to mount.  Stopper and hose assembly is pressed into bottom of funnel. Note stopper extending from bottom of funnel.

Drill two 3/16" diameter holes in front of barrel for mounting diverter.  Holes should be centered on front of barrel and located 2" and 3" below the bottom side of the lip at the top of the barrel.     

Leaching chamber made from bottom half of 5 gallon bucket.  1/2" diameter holes are drilled through side of bucket near top.  One hole is required for each hose. 

Leaching chamber is buried so top is several inches below grade.  In a 2 or 3 barrel system, only one chamber is required.  Note 2-1/2" diameter hole drilled into top of chamber.  This allows future inspection of chamber. 

 Leaching chamber should be centrally located and hoses from all barrels led into it.  Note: Drain hoses must be level or preferably downhill throughout their entire length.  Uphill sections, even short ones, will tend to stop urine from flowing. 

4" PVC plumbing cap covers hole on chamber top.  Note urine drain hose exiting front of barrel.  Also note 1/2" plastic cable clamps and 1/2" stainless steel machine screws securing drain hose.  

Men's urinal made from FloTool Giant funnel.  Stopper is same as used in making urine diverter.  Note that urinal is clearly marked for visitors.

Top view of urinal showing rubber stopper/drain hose in bottom of funnel.  Drain hose for urinal can be plumbed into leaching chamber for toilet if urinal is within 5-6' of leaching chamber.   Otherwise, plumb hose into separate leaching chamber.     


Handwashing bucket and urinal mounted on pipe.  Note that bucket and urinal are clearly marked for visitors.

Notes on construction:

--#10 stainless steel fasteners are used for securing the urine diverter to the barrel, for securing the urine drain cable clamps to the barrel and for securing the men's urinal to whatever surface it's mounted on.  Holes for these fasteners should be drilled using a 3/16" diameter drill bit.  

--The two holes for mounting the urine diverter to the barrel should be centered on the front of the barrel, about 2" and 3" below the lip at the top of the barrel (see photo above).  Inserting the urine diverter fasteners through these holes is easier if the holes are a bit larger than 3/16" diameter (7/32" is good)     

--The hole for the urine drain hose to exit the barrel should be 1/2" in diameter and centered on the front of the barrel, about 12" below the top of the barrel.  

--The urine drain hoses, one from the men's urinal and one from each barrel, will go into holes drilled near the top of the 5 gallon bucket leaching chamber.  These 2 holes should be 1/2" diameter. 

--Take care to be sure that hoses are level or downhill all the way from urine diversion funnels to leaching chamber.  If not, air bubbles may form in uphill sections, preventing urine from flowing. 

--Insert the hose into the funnel (this applies to both the urinal funnel and the diverter funnel), then press the hose into the rubber stopper.  Use soapy water on the end of the hose and on the rubber stopper to help get the hose into the stopper.  Gently press the stopper down into the funnel for a liquid-tight seal. 

 

Notes on use:

--The urine diversion system so effectively keeps urine out of the toilet barrel that some urine or water may have to be poured back into the barrel periodically to maintain sufficient moisture for effective decomposition.  

--Occasionally pieces of cover material may fall into the urine diverter.  If so, remove the screen from the diverter, turn it upside down and spray it clean with squirt bottle used for wetting toilet paper.  

--Check bottom of diverter occasionally to be sure rubber stopper around urine drain hose is snug.  A loose stopper can allow excessive amounts of urine to enter the active barrel, causing anaerobic conditions and resulting odors.  

 

Materials List for Urine Diversion System

 Urine Diverter (per barrel):

--Funnel, FloTool Super Quick Fill #10714WR                                                 $4.00 (AutoZone)
--Fuel line, 1/4” I.D. 8'@$1.20/ft.                                                                         $9.00 (AutoZone)
--Rubber stopper, 1" top dia., 3/4" bottom dia., 1" high                                   $1.00 (Ace)
--Cable clamps, 1/2” plastic, 3@$.20                                                                $1.00 (Ace)
--Machine screws, stainless steel, pan-head #10-24 X 2”  2@$.40              $1.00 (Ace)
–Flat washers, stainless steel, #10  4@$.20                                                    $1.00 (Ace)
--Nuts, stainless steel, #10-24  11@$.15                                                          $2.00 (Ace)
--Machine screws, stainless steel, pan-head #10-24 X 1/2”  3@$.20           $1.00 (Ace)
--Sink screen, Danco # 88822                                                                           $4.00 (Home Depot)

                                                                                                          __________________________
                                                                                                                              $24.00 

 Men's Urinal:

--Funnel, FloTool Giant  # 10705                                                                     $5.00 (AutoZone)
--Fuel line, 1/4” I.D., 1/2" O.D.   4'@$1.20/ft.                                                  $5.00 (AutoZone)
--Rubber stopper, 1" top dia., 3/4" bottom dia., 1" high                                $1.00 (Ace)
–-Cable clamps, 1/2” plastic, 3@$.20                                                            $1.00 (Ace)
                                                                                                            __________________________
                                                                                                                           $12.00

 Leaching Chamber:

--5 gallon plastic bucket, 1 @ $4.00                                                                $4.00 (Hardware Store)
                                                                                                            __________________________
                                                                                                            
                                                                                                            Total         $40.00