COMMON SEPTIC SYSTEM PROBLEMS
Blackout - Brownout
Contrary to popular opinion, the SBCWD is not set on deforestation of Stinson Beach. The
District staff does want to let customers know of the serious problems roots cause in and
around your onsite wastewater disposal system. Roots can clog pipes, break apart tanks,
infiltrate the gravel in your leachfield and render a system completely inoperable. The
Monterey Pines and Cypress seem to be the main villains, but the staff has seen problems
caused by Eucalyptus, Bay, Junipers and Ice Plant. In the follow-up to your Routine
Inspection, staff will advise you to have roots removed if we see them infiltrating into your
tank. Also if your leachfield was slow to accept the applied hydraulic loading during
inspection, we will require that you investigate the cause. If you act promptly and remove
the roots, you may be able to salvage your system and keep it operational.
Customers ask for recommendations regarding landscaping choices. The District office
has plant lists from Sonoma County that may guide you with your landscaping choices.
The local landscapers are also a wonderful resource. Please keep in mind that typically
your system is about 12 to 18 inches below the surface and that plants with invasive or
deep roots must be kept from the leachfield area.
If a plumbing back-up occurs suddenly, chances are it is not a problem with your septic
system, but a blockage between your household plumbing and your tank. You should
have a sanitary clean-out so that a plumber has access to your household server line to
clear the blockage. Disposal of non-degradable paper products can clog the inlet to the
tank. Tree roots can also infiltrate the household server line.
A sudden plumbing back-up can occur if the septic system relies on a pump, and either the
pump has failed or there has been an interruption in electrical power. If you suspect you
have a pump problem, contact a septic system contractor. The District maintains a list of
local contractors who are licensed to work on systems.
If your plumbing is running slowly, and if either this has been a gradual process or occurs
seasonally, then the problem may be associated with your septic system. In our
experience, a key culprit is roots. Again, contact a septic system contractor for root
removal and remove trees and hedges in the vicinity of your system.
If your plumbing works great in the summer, but is sluggish in the winter, you may have a
serious problem of groundwater intrusion into your system (i.e., your leachfield is flooded
with groundwater). This is the sort of siting problem that was not addressed when the
early systems were installed. The District will work with you to help understand the
seasonal disposal limits of your system, and if your system has to be replaced, the District
will allow a "less-than-code" system through the waiver process.
Odors emanating from a septic system can be indicative of a saturated field. During
normal use of an unsaturated system, the gases in the septic tank will pass with the
wastewater into the soil and be absorbed. If a field is saturated, the gases tend to migrate
up the plumbing vents and the neighbors will notice a "septic odor". A carbon filter is
available for installation on the roof vent to scrub these unpleasant odors. Immediately
prior to and during the routine inspection, the District inspector will note if there is
significant odor associated with a particular system, and if the system appears to be
saturated and not functioning properly, the owner will be notified. Odor associated with
surfacing effluent is of serious concern to the District.
Blackout - Brownout
The lights have gone out, you are scrambling around for candles and the last thing on your
mind is your septic system. If you have a gravity system, your sewage disposal needs will
be met for the duration of the power outage. If your system incorporates a pump, the pump
will not function until the return of power. To prevent sewage from backing up in your
plumbing, the household must minimize all wastewater generation. Typically, a system
has 200 to 300 gallons of emergency storage just for this occurrence and since your
electrical appliances (washing machine, dishwasher and electrical hot water heater) would
not be working, the household will naturally be using less water. When power returns, you
may hear an alarm sound because the alarm has been triggered by the high water
conditions in the tank. After the pump lowers the effluent level, the alarm buzzer should
Several years ago, Stinson Beach experienced a prolonged period of low voltage
(brownout). This condition can destroy refrigerator compressor motors, furnaces, freezers
and septic system pumps and panels. This happened to over a dozen of our customers
that have sand filter systems because during the brownout, the rain water infiltrated into
the sand filters causing the external basin pump to try to come on even if no one was
home. The motor contacts in the panels were destroyed and in some cases the pumps
had to be replaced. To prevent this from happening to your system, a low-voltage
protector can be installed to isolate the panel and pump from the low-voltage condition.
Sand filter owners may want to consider this option with their electrician.
There are several reasons why the alarm on your septic system might sound. All are
important, and no alarm should be ignored.
- There may be a pump failure or an interruption of power to the pump. If the pump
is not functioning, sewage will fill a septic tank or sump basin until the alarm
- There may be an electrical short in the alarm electrical system. There may be a
- For systems utilizing timed dosing, if the household has exceeded its maximum limit,
an alarm will sound and the pump will distribute a small amount of effluent to the
sand filter to immediately relieve the flooded condition. The household must refrain
from disposing of excess wastewater immediately, so that the system will not be
overused. Each time this "high-use" alarm sounds, an override counter in the
electrical panel will record the event. District staff tracks these counts for each
system to ensure compliance with the Discharge Limit.
Along with the spring wildflowers, Stinson Beach also tends to have a proliferation of
mosquitoes this time of year. District staff has met several times with personnel from the
Marin/Sonoma Mosquito and Vector Control District to discuss the problems in town.
Basically, your septic tank can be an excellent breeding ground for mosquitoes, but the
little devils have to find their way in and out of your tank. If your tank has PVC risers with
bolted fiberglass lids with neoprene gasket, you can be assured that this provides a
positive seal against mosquito entry. To further protect against mosquito entry, please
ensure that all of your plumbing vents on your house are covered with screening to prevent
mosquitoes entering and then leaving your system.
Please remember that anything that holds water can be a breeding ground for mosquitoes:
buckets, planters, ponds, rain gutters can all be a source of standing water. In previous
years, District staff would add juvenile hormone pellets to the tanks to prevent the
mosquito larvae from maturing. This was found to be a temporary solution and as soon
as the hormone concentration was reduced through usage of the system, the mosquitoes
would be back. The Marin /Sonoma Mosquito and Vector Control District reiterates that
the best approach for controlling mosquitoes is to prevent them from breeding by
eliminating or restricting access to their breeding sites.
Effluent ponding in a leachfield, breaking out down hill from a system or flooding out the
top of the tank is a serious concern to the District and will be addressed immediately. If
these conditions are observed during inspection, the property owner will be notified
immediately and the Discharge Permit will be revoked. If a report comes into the District
regarding suspected surfacing effluent, the District Inspector will investigate promptly.
Please limit your exposure to suspected untreated effluent. Keep pets and children from
contact and please contact the District with your complaint.