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INTRODUCTION
HISTORY
M M Ifliere can you find herons
 Mflajv roosting in trees and 31A miles
 W W of public access trails on the
edge of San Pablo Bay? The answer is
at Las Gallinas Valley Sanitary District's
Wastewater Reclamation Project in
Marin County, California. The District
has created a multi-faceted reclamation
project that includes a freshwater
marsh, irrigated pasture, storage ponds,
a saltwater marsh and miles of trails for
hiking, biking and bird watching.
       regional planning effort for
       eastern Marin and southern
          oma counties began in the
early 1970's. The goal of the planning
was to improve effluent water quality
to meet the increased requirements of
the Clean Water Act. The best apparent
alternative identified in 1977 was to
discharge treated effluent to the shallow
waters of the Bay, but only on high
tides, and to begin reclamation for
landscape irrigation.
   The agencies determined that this
did not afford the shallow waters of San
Pablo Bay, the northern most portion of
The District has created a
multi-faceted reclamation
project that includes a fresh-
water marsh, irrigated pasture,
storage ponds, a saltwater marsh
and miles of trails for hiking,
biking and bird watching.

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 San Francisco Bay, enough protection.
 They decided to require an elimination
 of any discharge of treated wastewater
 effluent to the shallow fringes of the
 Bay and its tributary creeks during the
 summer months.
   The planners were frustrated by the
 moving target, but they went back to
 the drawing boards and developed a-
 plan for treatment and disposal that
 would meet all of the requirements.
 In order to meet a requirement of no
 summer discharge the plan needed to
 include storage capacity and alternative
 disposal options. So they developed a
 project that included many forms of
 reuse and disposal.
   Las Gallinas'  wastewater reclamation
 project is a 385 acre complex including
 200 acres of irrigated pasture, 40 acres
 of storage ponds, a 20 acre freshwater
 wetland, a 10 acre  salt marsh, and land-
 scape irrigation. The District has an
 agreement with the local water agency
 for reclamation of up to 350 million
 gallons of treated effluent per year for
 landscape irrigation.
   Las Gallinas Valley Sanitary District
 was formed in 1954 by residents who
 were faced with serious health problems
 from failing septic tanks and pollution
 in Gallinas Creek. The District now
 serves a community of approximately
 30,000 people in northern Marin
 County. The District's influent is
predominantly residential including
discharges from some commercial and
light industry sources. The treatment
facility has a design capacity of
2.9 million gallons per day.
                                                    Las Gallinas
                                                    Valley
                                                    Sanitary
                                                    District
The planners were frustrated
by the moving target, but they
went back to the drawing
boards and developed a plan
for treatment and disposal.

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TREATMENT AND RECLAMATION
      The treatment plant was expanded
      and upgraded in 1984, when the
      reclamation project was construc-
ted. The project received state and
federal Clean Water Grant funds for
87.5% of the costs. The treatment
consists of grit removal, clarification,
two stage biofiltration, ammonia
removal, filtration, chlorination, and
dechlorination. The treated effluent
goes to a combination of the marsh, the
creek, or the storage ponds, depending
on the time of year. For nine months
out of the year the effluent from the
marsh is discharged to Miller Creek
and San Pablo Bay. During June, July,
and August, the discharge is stored in
40 acres of ponds and used to irrigate
the pasture and for the water agency's
recycling program.
   The 200 acres of pasture is subdivided
into sections so that it may be irrigated
on a rotating schedule. The irrigation
must be done in June, July, and August
to dispose of the effluent, however
depending on the weather and the
 needs of the pasture, it is usually
 irrigated through November. The
 irrigation schedule rotates among the
 fields with a goal of the disposal of a
 target number of gallons per month.
    Marin County is located on a narrow
 peninsula north of San Francisco. The
 County's drinking water reservoirs
 have relatively small watersheds and
 under extreme draught conditions have
 been nearly emptied. In seeking to
 develop new sources of water, the water
 district approached Las Gallinas to
 discuss the potential for reclamation.
The agreement that was developed
allows the water district to purchase up
to 350 million gallons of Las Gallinas'
effluent per year. The effluent receives
further treatment and is then sold for
landscape irrigation, helping the limited
potable water supply to stretch further.
  The 20 acre freshwater marsh/pond
was designed to incorporate a number
of different wildlife habitat types into a
single unit. This is accomplished by
varying the depths of the water  and the
types of vegetation that colonize each
area. The central area is the deepest,
more than six feet under normal opera-
tion. The deep central area is ringed by
a two foot deep zone that was designed
to become inhabited by emergent vege-
tation such as tall thin bulrushes. There
is an overflow zone that is only  inun-
dated during winter rains and when the
Las Gallinas Valley Sanitary District
"! Design Criteria
Design Year 	

1 Population 	
Average Dry Weather Flow 	
Peak Dry Weather Flow 	
BOD Loading 	
~]~sS Loading 	

Irrigated Pasture 	

Marsh/Pond 	
Storage Ponds 	

i Irrigated Landscaping 	

...2001

...34,711
. ..2.69mgd
. . . 4.3 mgd
. . . 5434 Ibs/day
...5738lbs/day

;..200 acres

. . . 20 acres
. . . 40 acres

. ..20 acres


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 marsh/pond is needed occasionally to
 store additional effluent near the end
 of the summer. The five islands are the
 final physical component of the marsh.
   The most important part of the
 marsh/pond is not its physical configura-
 tion but its biological inhabitants. The
 wide variety of plants and animals make
 the area interesting to the many visitors
 that walk, jog, or bike around the
 perimeter. There are many regular
 bird watchers that keep track of the
 resident and migratory populations that
 use the reclamation project. Members
 of the Marin Audubon Society have
 observed over 147 species of birds in
 the reclamation project areas.
   There are over 40 species of plants in
 the marsh/pond ranging from submerged
 pond weeds to emergent cattails. There
 are willow trees and acacias on the
 islands, grasses, and shrubs on the
 banks. The grasses on the islands
 produce seeds that are eaten by small
 rodents and serve as cover for water-
 fowl nesting. Mallards, coots, and
 Canada geese nest and raise their young
 at the marsh/pond. A portion of one of
 the islands is barren and has a gentle
 slope up from the water. This area is a
 favorite resting place for the cormorant.
   The island's trees provide roosting
habitat for a wide variety of birds
including snowy and great egrets,
black-crowned night heron and the
great blue heron. Occasionally there is
even competition for roosting space
among the tree branches. A  long-eared
owl rested not so peacefully, in a willow
tree one February afternoon when a
 red-shouldered hawk perched barely
 3 feet above its head in the same tree
 and screeched incessantly, trying
 unsuccessfully to get the owl to move.
   The wading herons and egrets and
 the diving pelicans and cormorant are
 probably attracted to the wetland not
 only for resting but to feed on the plen-
 tiful small fish in the pond. The flock
 of dozens of large white pelicans that
 frequent the marsh are a favorite of
 visitors. There are small mosquito fish
 as well as carp that grow to fourteen
 inches in length. Many other animals
 use the marsh/pond including noisy
 bullfrogs, snakes that shed their  old
 skins intertwined among the tall grasses,
 raccoon, jack rabbits, deer and muskrat.
The muskrats aren't always welcomed
by the wetland manager because they
tend to dig tunnels in the levees.
  The salt marsh restoration project
was completed to diversify the types
of wildlife habitat. The salt marsh is
fed by water from the Bay and does
not receive any treated effluent.

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WATER QUALITY
      The Las Gallinas Valley Sanitary
      District produces a high quality,
      advanced secondary effluent.
The average flow in 1992 was 2.7
million gallons per day, during the
months when the effluent is discharged
to Miller Creek and the Bay. The
purpose of the treatment plant and
reclamation project is to keep as much
of the pollutant load from entering the
environment as possible. In 1992 the
plant removed 95% of the organic
material that would enter the creek
and bay. These biochemical oxygen
demanding substances would use
oxygen to complete decomposition.
It is this oxygen that is needed by fish
and other aquatic organisms for their
survival. The concentration of ammonia
in the effluent is reduced substantially,
to a level that is not harmful to fish in
the marsh/pond or the creek.
Las Gallinas Valley Sanitary District
Effluent Water Quality, 1992 Averages

Parameter

Monitoring
Frequency 
1/mo
" 1/mo
1/mo
	 " 	 T/mo '
1/mo
1/mo
1/mo
1/mo
1/mo
4x/yr
Average
oncentration
9.9mg/L
14mg/L
<5mg/L
0.06ml/L/hr
6.6 units
2.3mg/L
<2ug/L
<1 ug/L !
<2ug/L
18ug/L
<10ug/L
<2ug/L
0.3ug/L
3.5ug/L
2.3ug/L
75ug/L
<50ug/L

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 COSTS AND BENEFITS
      The reclamation project was
      constructed in 1984 for a cost of
      $6.5 million dollars, including the
land acquisition. Approximately 87.5%
of the project funding was from state
and federal Clean Water Grant funds
administered by the Environmental
Protection Agency. The project was
recognized for Engineering Excellence
in a competition sponsored by the
Consulting Engineers Association of
California and indeed the residents of
the District are proud of the treatment
system and enjoy the benefits of the
reclamation project. Each and every day
people can be seen walking dogs, gazing
through binoculars at their favorite
birds, and jogging around the marshes.

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Developed by Woodward-Clyde
   Consultants
Project ManageróFrancesca Demgen
EPA Project ManageróRobert Bastian
Graphic DesignóChris Dunn
This brochure was created with funding
from the U.S. Enviromental Protection
Agency. Requisition No. A22190.

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