David E. Ross wrote:
....
Where I live, sewage (not merely gray water) is treated at a plant that
is mostly gravity fed. The input is from both residential and
commercial sources. At the plant, liquids are separated from solids.

arg! precisely the problem which should be avoided.
combined residential and commercial sewage... always a
bad idea as it gives the businesses a free pass to let
trace contaminants and odd chemicals off site without
compensation to the treatment facility to manage the
results and it then also contaminates all the wastes so
that they can't be reused. which is why later on you
mention that they can't be reused in veggie gardens
without restrictions.


Liquids are "tertiary" treated and then pumped back uphill to irrigate
parks, school playfields, greenbelts, and two golf courses. So far, the
use of such reclaimed water is not covered by drought-induced
restrictions. Furthermore, the ability to use this on school playfields
means it is biologically safe. However, the reclaimed water contains
too much dissolved minerals for domestic use. Because of that,
individual homeowners are not allowed to tap that source; there is a
concern that amateur plumbers -- the homeowners -- might accidentally
cross-connect a reclaimed water line with a potable domestic water line.
This concern about contaminating potable water with reclaimed water
also means that the mains carrying reclaimed water operate at a lower
pressure than potable mains.

The solids are composted to the extent that they too are biologically
safe. Dried, this compost is free to anyone who brings a container --
including a truck -- to the composting site. Again, the presence of
dissolved minerals (possibly heavy metals from commercial sources of
sewage) is a concern. Thus, users of the compost are advised to place
only a small amount in beds containing edible plants such as vegetables
and fruit trees. Larger amounts can be used on ornamental plants.

yeah, but once it's applied then it's basically
spreading a contamination issue around. i wonder
what percentage of it is actually used instead of
being landfilled (or in some cases incinerated which
can spread the heavy metals around even more).


All this is a result of political pressure from homeowners downstream
from the sewage plant in Malibu. They wanted to restrict the plant's
operation because they feared they too would be required to abandon
their septic tanks and instead connect to sewer lines, thus opening
Malibu to increased development and population density. After the
sewage plant succeeded in developing a market for reclaimed water,
however, those same NIMBY homeowners changed their pressure to require
some of the reclaimed water to flow down Malibu Creek to maintain
riparian wildlife, including fish that had not been in the creek for
decades.

if the water is there and the stream benefits why
would this be bad? it returns a previously damaged
river to some forms of life and gives fish habitat
that they'd lost.


The natural flow of water in Malibu Creek above the sewage plant is
contaminated by wildlife in the Santa Monica Mountains National
Recreation Area.

i wouldn't call it contamination but that's just me.
animals poop/pee. just if it is safe or not for people
to swim in it or fish it or ...


Now, the Malibu homeowners have convinced California
state authorities to mandate that the flow of water in the creek below
the sewage plant to be cleaner than the natural flow above the plant.

with modern wastewater treatment plants this is actually
not uncommon at all. the troubles from treatment plants
and sewage is often storm water overflows driven by combined
waste and storm water drains. in many cities here they are
gradually removing such combined systems to give the rivers
a better chance of not being contaminated by sewage overflows.
and it's working. things are gradually improving. but it's
taking time and a lot of money. money which would not be
required to be spent had the systems been dry compost forms
instead. ah well...


I pay over $500 a year in sewage fees for only my wife and me. There is
no winning, only different ways of losing.

that is water and sewage cost or just sewage/disposal
cost?

even if we include the cost of the whole plumbing system
here and septic field we could get it to around $300/yr but
that's because we've been here almost 20 years now (wow how
time has gone by!). it doesn't cost that much to have the
tank pumped and taken to the sewage treatment plant. i still
don't like it. a dry system would be much cheaper. sawdust
can be had by the truckload here for not much, leaves and
dirt are free. the gardens would be much happier too.


songbird