Another View on Pump-to-Gravity

In response to your article on pump-to-gravity onsite systems (Onsite Installer, December 2011), I have worked for 22 years in the northernmost county in Virginia. I differ 180 degrees with your article. Our experience is quite opposite, and that is interesting because usually that is not the case with articles I read, such as yours. 

We have found, and we have done studies, that pump-to-gravity systems are our most reliable systems with the lowest failure rate and a low-maintenance cost. Pressure systems such as low-pressure distribution and drip systems are high maintenance. Due to orifice plugging and valve clogging in the LPD systems, we have poorer distribution than with the gravity pumps.

I must qualify this with the fact that we design all of our gravity pump systems to pump at least 3 gpm per lateral and 0.4 gallons per foot of trench (3 feet wide). I have inspected many of these systems and right after running the pump I find water at the ends of the lines, especially when the lines are 70 feet or less in length.

So my thought is that we are getting total trench distribution without the larger pump size, design and clogging issues of pressure systems. Also, since most of these systems pump only once per day, it allows the trench to dry out and get oxygen between pump events, thus reducing the biomat. Of course, that also kills off the bugs, so I don’t know about the quality of treatment, which probably would not be as good as in a time-dosed situation.

Jerry Franklin

Loudoun County, Va.

Failing Systems

In response to your column of failing septic systems (“Failures: How Prevalent?” Onsite Installer, February 2012): I have been a septic system inspector licensed in Massachusetts since the first day the Title 5 code came into effect in April 1995.

Since then, I have conducted 1,539 inspections, mostly in the western part of the state. Here we have a lot of mountaintop soils, which are glacially compressed, silty and rocky. We also have our fair share of wetlands. Most of my inspections were also witnessed by a local Board of Health official, as sometimes required by local ordinances.

Title 5 is a severe code and has caused much wailing. It will fail a septic system if any part of the leaching system is ever in groundwater, or if the leachfield backs up as little as an inch of water, as seen in the distribution box. I don’t like to fail a septic system, but it sometimes leaves little room for doubt.

Over the years, I have kept a full database, so I can state that 324 systems failed, so that is a 21 percent failure rate.

Tom Leue, R.S.Homestead Engineering Inc.d.b.a. Homestead Inc.Williamsburg, Mass.