Wastewater discharge method and system

Abstract

The present application provides a method and system for disposing wastewater effluent through laterals placed over a drain field without the need to level the terrain. The method provides calculating sizes of one or more orifices in positioned along the length of the laterals.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 
     
         1 . A method of disposing wastewater over a drain field comprising the steps of
 a) providing a wastewater effluent to one or more laterals;   b) providing a datum string line over a portion of the drain field, the datum string line extending from a first end of one of the one or more laterals to a second end;   c) measuring a first distance between the datum string line and a first of a plurality of points on the one or more laterals therebeneath;   d) measuring a second distance between the datum string line and a second of the plurality of points on the lateral therebeneath;   e) calculating a difference between the first distance and the second distance to determine a ΔD   f) calculating a discharge pressure at an orifice in the lateral at the first distance based on the ΔD;   g) calculating a size of an orifice at the second of the plurality of points based on the discharge pressure; and   h) providing an orifice at each of the plurality of distances along the lateral, such that the wastewater is disposed over the drain field through the orifices along the lateral.   
     
     
         2 . The method of  claim 1 , wherein the discharge pressure at the orifice is the sum of an initial pressure through the lateral expressed in ΔD, and a change in pressure due to elevation change, less a pressure due to friction loss. 
     
     
         3 . The method of  claim 1 , wherein a size of an orifice is proportional to a discharge flow rate at said orifice. 
     
     
         4 . A method of disposing wastewater over a drain field comprising the steps of:
 a) providing a wastewater effluent to one or more laterals;   b) providing a datum string line over a portion of the drain field, the datum string line extending from a first end of one of the one or more laterals to a second end;   c) measuring a first distance between the datum string line and a first of a plurality of points on the lateral therebeneath;   d) measuring a second distance between the datum string line and a second of the plurality of points on the lateral therebeneath;   e) calculating a difference between the first distance and the second distance to determine a AD using the formula:
     ΔD=D*−Di   (1)
 
 where D* is the distance between the datum string line and the lateral at the first end of the lateral and 
 Di is the second distance; 
   f) calculating a discharge pressure at an orifice in the lateral at the first distance using the following formula:
     P   discharge   =P   int   +ΔP   e   −ΔP   fl   (2)
 
   where P discharge  is the discharge pressure at the orifice,
 P int  is an initial pressure or, if at a second or subsequent distance, the pressure at the preceding distance, 
 ΔPe is a change in pressure due to elevation change expressed in ΔD feet of pressure (above), and 
 ΔP fl  is a pressure due to friction loss; 
   g) calculating a size of an orifice at the second of the plurality of points using the following formula:   
       
         
           
             
               
                 
                   
                     
                       orifice 
                        
                       
                           
                       
                        
                       size 
                     
                     = 
                     
                       
                         
                           discharge 
                            
                           
                               
                           
                            
                           flow 
                            
                           
                               
                           
                            
                           rate 
                         
                         
                           16.37 
                           × 
                           0.6 
                           × 
                           
                             
                               ( 
                               
                                 P 
                                 discharge 
                               
                               ) 
                             
                             0.5 
                           
                         
                       
                     
                   
                 
                 
                   
                     ( 
                     3 
                     ) 
                   
                 
               
             
           
         
         
           where discharge flow rate is a desired discharge flow rate at a given orifice and 
           P discharge  is the discharge pressure at the orifice; and 
         
         h) providing an orifice at each of the plurality of distances along the lateral, such that the wastewater is disposed over the drain field through the orifices along the lateral. 
       
     
     
         5 . A system for disposing effluent wastewater from a wastewater effluent line comprising one or more laterals connected to said wastewater effluent line, the laterals comprising orifices determined by the method defined in  claim 1 .