8-inch VCP gravity sewer exfiltration rate? No Groundwater.
8-inch VCP gravity sewer exfiltration rate? No Groundwater.
(OP)
We are searching for the source of the below formula, alleged to be a pipe leakage rate for small diameter 8" VCP gravity sanitary sewer pipe by an "expert", with no citation/source given. The leakage is expressed in Liters per meter of pipe length, and it has been used to estimate the leakage rate of a "newly installed" 8-inch VCP gravity sewer pipe flowing at about one-half inch depth, serving three homes, on a steep .094 slope:
Leakage rate = 0.37 to 0.92 Liters/hour/meter of pipe; or 0.1 to 0.25 gallons/hour/39 inches of pipe.
Note there is no pipe size, slope/velocity, flow quantity, or pressure head, only x Liters per hour per length of pipe?? This may have come from an urban drainage or flood flow source??
We have searched everywhere including the EPA/CDM 2000 "Exfiltration in Sewer Systems"
htt p://www.ep a.gov/nrmr l/pubs/600 r01034/600 r01034.pdf
and the EPA/CDM Project Summary 2003 at
http ://www.epa .gov/nrmrl /pubs/600r 01034/600s r01034.pdf
"Exfiltration in Sewer Systems Project Summary" March 2003
and numerous other sources, WEF,Civil Engineering Database, and others to no avail. Where does this formula come from or is it completely bogus???
Your opinion/assistance will be greatly appreciated.
Leakage rate = 0.37 to 0.92 Liters/hour/meter of pipe; or 0.1 to 0.25 gallons/hour/39 inches of pipe.
Note there is no pipe size, slope/velocity, flow quantity, or pressure head, only x Liters per hour per length of pipe?? This may have come from an urban drainage or flood flow source??
We have searched everywhere including the EPA/CDM 2000 "Exfiltration in Sewer Systems"
htt
and the EPA/CDM Project Summary 2003 at
http
"Exfiltration in Sewer Systems Project Summary" March 2003
and numerous other sources, WEF,Civil Engineering Database, and others to no avail. Where does this formula come from or is it completely bogus???
Your opinion/assistance will be greatly appreciated.





RE: 8-inch VCP gravity sewer exfiltration rate? No Groundwater.
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: 8-inch VCP gravity sewer exfiltration rate? No Groundwater.
Note that Liters/hour/meter of pipe is not the same units as liters per millimeter of pipe diameter per kilometer per day.
I don't know where the number originates, but it is a valid number and is listed in the Standard Specifications.
The leakage for a 250 ft sewer actually calculates to 91 gal. per day
You also need to have the testing procedure spelled out.
Attached is the Standard Specification for leakage testing.
RE: 8-inch VCP gravity sewer exfiltration rate? No Groundwater.
Now, with regard to same and not knowing any more of the specific case nor time period when the specific pipeline was designed/installed, the expressions "completely bogus" or "BS" could be a little too strong characterizations in some circumstances, as who knows what leakage rates may have been locally accepted by inspectors (or even specified by whatever authorities) over many decades? In this regard, the spokesfolks for the major clay pipe industry in the USA in effect even contemporarily claim that a significant leak path "was" [see e.g. http://w
Everyone have a good weekend.
RE: 8-inch VCP gravity sewer exfiltration rate? No Groundwater.
240 gallons per inch of pipe diameter per mile per day *(Y)*(X) = Total Gallons of Leakage per day
where X is the miles of pipe
and Y is the diameter in inches
RE: 8-inch VCP gravity sewer exfiltration rate? No Groundwater.
BASED ON PUBLISHED LITERATURE FROM VARIOUS
SOURCES FROM E.P.A. TO LOS ANGELES COUNTY TO ORANGE COUNTY
SANITATION DISTRICT, THERE HAVE BEEN STUDIES THAT IDENTIFY
SEWER LINE LEAKAGE AND THE RATES OF SEWER LINE LEAKAGE PER
FOOT OR PER METER. THOSE PUBLISHED RATES EQUATE TO 0.37 TO
0.92 LITERS PER HOUR PER METER OF CLAY SEWER LINE.
Q DO YOU HAVE ANY OF THOSE REFERENCES IN YOUR
NOTEBOOK?
A NO, I DON'T.
I HAVE THE SOURCES GENERALLY CITED BEING BROWN
& CALDWELL, 2005; ORANGE COUNTY SANITATION DISTRICT, 2005;
CONFERENCE OF URBAN DRAINAGE MODELING, 2004;
CITY OF LOS ANGELES BUREAU OF SANITATION, 2006; E.P.A., 2003;
AND CAMP, DRESSER & MCKEE, 2000.
There you have it. I have been an expert witness in about 30 pipe cases from FL,OH,NJ,WA,CA,AZ,AL,etc., including the USA v. Miami Dade Metro and the State of Florida for the US DOJ, and I have never seen this formula. Black Magic, I guess. I just want to know wher it came from, if not just smoke, probably mis-used.
RE: 8-inch VCP gravity sewer exfiltration rate? No Groundwater.
I would go back and question the fellow on how to conduct the leakage test. If he can not come up with a testing procedure, it will weaken his testimony.
RE: 8-inch VCP gravity sewer exfiltration rate? No Groundwater.
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: 8-inch VCP gravity sewer exfiltration rate? No Groundwater.