1. San Cristóbal, Galapagos
Municipal Waste Water Treatment
Analysis and Action Plan
USFQ Students: Molly Overgaag, Arielle Shingles, Michael Quade
Legislation/Policy
Ecuador has implemented a great deal of policies and legislation that protect the environment in the past
century, however, it is important to note that at the root of this problem relating to sewage treatment is
that the majority of the laws are not enforced. First, it should be acknowledged that Ecuador was the first
country to establish rights of nature in its constitution (Constitution). This means that the Ecuadorian
constitution recognizes certain intrinsic rights of nature that are independent of its value to humans
(Constitution). The rights of the nature clause of the constitution also establishes that the government has
the responsibility to protect and promote respect for the environment (Constitution). It also establishes the
right of restoration for nature (Constitution) . Most importantly pertaining to the issue of sewage treatment
is the precaution set forth in the constitution when it comes to activities that could cause extinction,
ecosystem destruction or alteration of natural cycles (Constitution). This means that caution should be
used when there is a possibility that one of these damaging instances could occur.
There are a great deal of laws that deal with management of the environment. For example, the
Environmental Management Law was passed in 1999 (Env. Mgmt. 1999). This law established the right
of people to live in healthy environments, free of pollution (Env. Mgmt. 1999). It also delineated specific
responsibilities for the public and private sectors in creating limits, sanctions, and controls in terms of
environmental protection (Env. Mgmt. 1999).
Most important are the special laws that apply solely to the Galapagos. The Organic Law for the Special
Regimen for the Conservation and Sustainable Development of Galapagos, also known as LOREG
implements a special regime for governing the islands (LOREG 1998). Policies set forth by this law are
concerned with protection and conservation, as well as promoting human health (LOREG 1998).
According, to this law, invasive species are the greatest threat to biodiversity on the islands (LOREG
1998). Furthermore, LOREG also created the National Institution for the Galapagos, or INGALA (LOREG
1998). INGALA is tasked with coordinating with different governmental and global organizations to
manage development on the islands in an environmentally sustainable way (LOREG 1998).
There are also international policies and legislation that pertain to the Galapagos. The Galapagos Islands
have been designated a World Heritage Site by the United Nations Educational, Scientific, Cultural
Organization, more commonly known as UNESCO (unesco.org). The Galapagos Islands received this
distinction because they are considered an example of important biological processes and natural beauty
(whc.unesco.org). The goal of this United Nations body is to create a global environment of preserving
cultural and natural treasures (whc.unesco.org).

2. Description
San Cristóbal (Chatham) is the easternmost island in the Galápagos archipelago. It is administratively
part of San Cristóbal Canton, Ecuador and under this context is being viewed for its current wastewater
system.
A wastewater system, or urban sewer system, is defined as; 'the set of works for the collection,
conveyance and disposal of waste water, the mixture consisting of liquid wastes discharged from
residences, public, educational and commercial properties; liquid wastes discharged from industrial
premises (absent in Puerto Baquerizo Moreno) ; and groundwater, surface and rain water entering the
sewer as infiltration
1
.
In 1982, 'Environment Minister, Marcela Aguiñaga, and the Mayor of San Cristobal, Pedro Zapata,
launched the “Wastewater Plant Treatment in Puerto Baquerizo Moreno," which meets the requirements
to ensure environmental operation.
The wastewater treatment plant had the latest technology of that time period, including: a chemical
treatment plant, an activated sludge plant with aerobic process, an aeration system with high flow blowers
and pressure filters and silencers with electric motors, a raft of interconnected disinfection with discharge
line of the plant, and a pumping system.
Some of the effluent discharge from the wastewater plant will be reused in organic gardens specifically
implemented by the municipality. Another part will be discharged to sea in compliance with the minimum
environmental standards for water quality, ensuring the health of marine ecosystems
2
.'
This wastewater treatment plant and pumping system was built with a population of around 2,000. Today
the population of Puerto Baquerizo Moreno is around 6,000, not including the 'floating population' of those
visiting the island, and is still using the same wastewater treatment system built in 1982.
'The urban sanitary sewer system of Puerto Baquerizo Moreno is the collection of wastewater tertiary
collectors (small diameter sewers where buildings are connected, usually buried under sidewalks)
passing secondary manifolds ( buried under the street) that collect wastewater from tertiary collectors and
lead to the pumping stations located near the coast. These pumps drive wastewater sequentially from the
lowest part of the city to the wastewater treatment plant (WWTP) located in the highest part of the city
center, next to Cerro Patricio.’
1
Empresa Metropolitana de Alcantarillado y Agua Potable de Quito - EMAAP-Q.
la EMAAP-Q EMAAP-Q, Quito, 2009.
2
Ministerio del Ambiente. (2009). Analysis and monitoring of water quality in Santa Cruz, San Cristóbal, and Isabela. Retrieved from
http://www.galapagospark.org/nophprg.php?page=desarrollo_sustentable_calidad_agua

3. Current sewage system is shown in the following chart;
Figure 1: working layout of urban sewer system in Puerto Baquerizo Moreno

4. Figure 2: locations of planned pumping stations and treatment center
Figure 3: Locations of planned pumping stations and unplanned discharge station
1. Playa de Oro Pumping
Station
2. Main Pumping Station
3. Waste Water Treatment
Center
1. Playa Mann Pumping
Station
2. Playa de Oro Pumping
Station
3. Punta Corola Discharge
Station (untreated)

5. The three pumping stations shown (Figure 1 and 3) and their operations;
'A pumping station is a set of structures, equipment and accessories to lift water from a lower level to a
higher or feeding pressure energy in a hydraulic system
31
'
1. Pumping station in Playa Mann: receives water from the Universidad San Francisco de
Quito ( USFQ ) and Galapagos Interpretation Center of the National Park and driving to
the next station through a line drive 50mm diameter PVC.
2. Pumping station in Playa de Oro: receives the waters coming from the station in Playa
Mann and wastewater districts in northern and central Gaza City. Drives the water
received to the main pumping station via a line drive PVC 2 inches in diameter.
3. Main pumping station: receives water from Playa de Oro and water districts on the
southern fringe of the city. It pumps the water received by a line drive made of PVC
pressure pipe , diameter 10", which goes by the street Manuel J. Cobos, then Av. Alsacio
Northia and up Av. Quito , ending at the WWTP located south of the headquarters of
CGREG and covering a total length of 1360m and a nearby slope to 50m
41
.
Each pumping station consists of a linear sequence of chambers, separated by slide gates and grilles.
The chambers are provided in a building (pump room) and are arranged as follows:
1. Screening chamber : Receives residual water from the well of entry and allows the step to the
next chamber through a grate for retaining solid of up to 10 mm in size, approximately .
2. Storage chamber : This tank provides a buffer volume of wastewater flow from excesses hosts
sewers for reasons such as failure pumping system .
3. Flume chamber: Equipped with a Parshall flume flow measurement allows entering the suction
chamber.
4. Suction chamber : Stores water to facilitate the submerged suction pumps.
The pumps in the suction chamber are submersible, or sub-pumps, and are arranged parallel to one
another to increase throughput capacity.
These pumps have the following characteristics:
● Two pumps alternate service operation,
o centrifugal ( pushing fluid away from center)
o submersible (sub-pump)
31
Empresa Metropolitana de Alcantarillado y Agua Potable de Quito - EMAAP-Q.
EMAAP-Q -Q, Quito, 2009.
41
Pablo Daza, Ing. MSc. (2014).
.Puerto Baquerizo Moreno, Provincia de Galapagos: Pablo Daza.

6. o Grundfos brand, power of 53 HP and voltage 460 V.
● A backup pump or stand -by
Pumps date back to the original facilities built by former Ecuadorian Institute of Sanitary Works.
Current State of Urban Sewage System
As of date, October 2014, the current urban sewage system is not able to properly perform its set duties
of wastewater treatment in compliance with the minimum environmental standards for water quality, set
forth to ensure the health of marine ecosystems, due to the following factors;
1. Natural Gradient and Location of Waster Water Treatment Plant (WWTP)
51
;
Note that the flow pattern of the system is very unique because of the position of the
WWTP. In general, water is forced by notoriously long distances and in an unnatural
cycle: the natural course of the water is in favor of the gradient field downhill , but the
plant is located in the highest part of the city which necessarily a pumping system is
required. From the ground water runs through the city center to download on a long
stretch along the same road that goes to the floor. Finally, without pumping system fully
operational , integrated urban sewer system loses the ability to debug prior to discharge
effluent into the sea , causing coastal pollution.
2. Playa Mann Station;
● There is no second backup pump installed , although there are necessary connections ,
which increases the risk of disconnection.
● Pump and driveline station are 50mm, but it is recommend to have at least 100mm in
diameter to prevent clogging.
● There is no mechanism that prevents overflow spills and pollution in case of malfunction of
the pumps.
● There is no emergency generator to supply 100 % of the power supply when there are
failures or voltage dips in the grid.
● There is no safety or signaling equipment needed to risks such as spills, fire or electric shock.
● There is accumulation of solids on the walls of the chambers of the wet season in the pump
and plumbing and electrical installations , which shows a lack of maintenance and cleaning of
several months or years.
● There is proliferation of cockroaches in humid chambers of the season.
● The civil work that involves pumping station is in poor condition in general: the door is
damaged, the holding room for maintenance personnel is in poor condition , no accumulated
rubbish , gardening is neglected and architectural aesthetics of the superstructure is
unpleasant and clashes with the environment.
● There is no proper ventilation system to control odors.
● The station does not have enough flood protection despite being located in an area of high
risk of tsunami inundation .
3. Playa de Oro Station (Muelle de Pescadores)
61
;
● For at least two months pumping station has suspended its operation for pump failure in
service. The submersible centrifugal pump is faulty effluent, Goulds brand , model WE0511H
51
Pablo Daza, Ing. MSc. (2014).
.Puerto Baquerizo Moreno, Provincia de Galapagos: Pablo Daza.
61
Pablo Daza, Ing. MSc. (2014).
.Puerto Baquerizo Moreno, Provincia de Galapagos: Pablo Daza.

7. 0.5 HP . The backup pump is the same but had been removed long before malfunction, so
the station operated with a single pump , until this single pump broke down , which for at least
two months caused wastewater to be continuously discharged into the bay on the south side
of Muelle de Pescadores, on the edge of the waterfront . It is known that these pumps failed
and often the cause of the suspected fault has to do with insufficient capacity and voltage
fluctuations in the grid. From 27 May 2014 the station resumed its service with a submersible
centrifugal pump Pentair brand , model MW200 power 2 HP , 4 times the capacity of the
previous pump, but was not installed backup pump of the same characteristics . On May 29,
2014 at 09:30, an inspection was conducted at the site and noted that the new pump was
operating shock and had not at that time to the sea. However, it is necessary to install a
backup pump just check whether this new pump installed is operating properly and has
sufficient capacity to evacuate during peak demand.
● driveline station is 50mm , but it is recommend to have at least 100mm in diameter to prevent
clogging.
● The drive line has an open section at Playa de Oro making it vulnerable to ultraviolet
radiation (broken plastic pipe and reduces their resistance to internal pressure) and
accidental breakage live load , so there risk of direct beach spills. In fact , a segment that has
been repaired multiple times by frequent breaks by pressure against the north end of the
wooden bridge that crosses the beach was observed.
● unions driveline are fixed - bell and spigot type . However, engineering practice recommends
acceptable flexible couplings (eg elastomeric seal joints ) to allow small displacements
without losing hermeticity .
● overflow mechanism for excess flow is not designed to prevent spills and contamination. It
has a modest dump in a pit at the start of the season over which pours the excess flow into a
pipe which discharges directly into the bay on the south side of the fishing pier. Prior to the
installation of the new pump was running continuously pouring entire flow collected at
shoreline and close to Playa de Oro. However , if the pump capacity is insufficient at peak
water consumption , could continue spills. On the beach there were frequent visitors and
groups of marine animals exposed to contaminated water.
● There is no emergency generator to supply 100 % of the power supply when there are
failures or voltage dips in the grid.
● There is no safety or signaling equipment needed to risks such as spills , fire or electric
shock.
● Electrical installations are unwilling safely to avoid electrical hazards (eg electrical
connections malformed insulation).
● There is proliferation of cockroaches in humid pump chambers.
● There is no proper ventilation system to control odors.
● The station does not have enough flood protection despite being located in an area of high
risk of tsunami inundation .
4. Main pumping station (Av . Charles Darwin and Manuel J. Cobos, corner)
71
;
● For nearly two months the station has been out of service. Service pumps have been
removed for maintenance on the mainland. Meanwhile only the backup pump is running ,
which does not have sufficient power to pump the flow to the WWTP reliably. Therefore, the
system pumps the untreated wastewater directly into the ocean.
● The material of pumps and drive lines in the suction chamber have corrosion protection, but
71
Pablo Daza, Ing. MSc. (2014).
.Puerto Baquerizo Moreno, Provincia de Galapagos: Pablo Daza.

8. this has deteriorated over time.
● The mechanism of flow in excess overflow is not designed to prevent spills and
contamination. The existing mechanism is a well entrance to the station with a modest
excess overflow pouring a tube that drains directly to the bay on the waterfront opposite the
building of the Municipality . Currently, it runs continuously, pouring untreated wastewater into
the waterfront of Playa de los Marinos.
● There is no emergency generator to supply 100% of the electric power supply failures when
there are voltage dips in the grid.
● There is a high risk of breakage by water hammer pressure in the lower level of the driveline
due to the following causes:
○ In the absence of an electric generator, a power outage would suddenly stop the
pumps and therefore interrupt the flow, which would cause significant ram stroke,
whereas the static load on the pumps (difference between the pump station to the
WWTP ) is large (close to 50m).
○ Currently only one pump operates, so at each stop the flow is stopped suddenly,
causing water backup.
○ There are no adequate equipment to hoist pumps for maintenance . The porch
holding submersible pumps are not designed to allow easy disassembly and removal
of pumps , forcing use simple hoists to lift the team , but having great difficulty to
move it to the floor.
○ The site is not provided with roads and access routes that allow the transport of the
pumps if they are transferred to maintenance
○ There is no safety or signaling equipment needed for risk as spills , fires , falls or
electric shock.
○ Cleaning of the screens occurs only during normal working hours and is not frequent
enough, so sewage most of the day is discharged into the bay.
○ No flow gauging performed in this pumping station, so that the flow characteristics in
the system is unknown
Water Quality

9. Stakeholders
A stakeholder is any individual, group or community living within the influence of the site or likely to be
affected by a management decision or action, and any individual, group or community likely to influence
the management of the site
81
.
The identified stakeholders for the urban sanitary sewer system of Puerto Baquerizo Moreno are as
follows;
● ecentralized utonomous o ernment o an Crist al
● Municipality
● Governing Council of the Special Regime Galapagos (CGREG )
● Galapagos National Park (GNP)
● an Crist al residents
● Tourists and Tourism sector o an Crist al
● ocal and nternational ishin com anies occu in waters located o o an Crist al
shores
● an Crist al usiness owners
● Marine and land wildlife, including ecosystems and biospheres in which they reside
Objective
This project aims to develop sustainable waste water management on San Cristobal Island of the
Galapagos Islands to maintain the well-being of people and their environment. In order to achieve this
outcome, it is necessary to implement a completely closed system when managing waste. This includes
all water being recycled through the inputs and outputs of waste as well as utilizing any left over waste in
the form of biosolids for fertilizer and agricultural purposes. When implementing a new waste water
management system, it is also crucial to disassemble the previous system. This will include removing
pipes used in the old sewage treatment system and assure that no previous sewage will be leaching
through soils or entering the ocean. In order to meet our objective, a committee must be established
through the municipality with the purpose of overseeing the disassembly and assembly of waste water
81
Mike Alexander. (2013). Management Planning for Nature Conservation A Theoretical Basis & Practical Guide. New York,
London:Springer Dordrecht Heidelberg.

10. systems as well as monitoring the progress of each process. A suitable monitoring strategy will include
both scientific methods and infrastructure planning.
Action Plan
Monitoring System
In order to monitor the system that is put in place, there must be a monitoring committee that is in charge
of waste water management. This committee will be responsible in ensuring that all pipes and processes
of the new treatment plant are functioning properly as well as monitor previous waste sites from the old
treatment plant to keep tabs on the water quality in these locations. For the new system, the committee is
responsible for mapping the entire waste water facility as well as the inputs and outputs. This includes
utilizing GIS to take coordinates and then converting these coordinates onto GIS software to spatially
demonstrate the new system. When checking the water quality in the locations that the four pipes used to
be located, the following should be monitored. There should be dissolved oxygen, pH, turbidity, and
phosphorus testing at each of the four pipe outlets. These tests can be conducted with a GLX probe,
secchi disk, as well as sample collecting and lab work on the water. Transects of 10M should be
constructed and have the same testing as previously stated. These transects should continue until the
results are synonymous with the transect location just previous of it.
Disassembly of Old Sewage System
The complete disassembly of the previous system will not be possible until the new system is in place
and has been fully integrated. However, certain elements of the current system can be modernized in
preparation. Namely, the pipe network of the old system needs to be updated in order to properly handle
the increased sewage load due to the current population size. The pipes of the old system were not
designed for this higher capacity of sewage. As such, wider pipes are an inevitable requirement before
the new system can be implemented. The replacement of these pipes poses a significant challenge, as
the network will need to be used constantly throughout the renovation. Hence, a piecewise reconstruction
method is necessitated:
● Temporary installation of alternate connection for a small portion of pipe further downstream.
● Diversion of the flow of sewage downstream through this temporary connection.
● Removal and replacement of the liberated pipes.
● Removal of temporary diversion, and restoration of flow through new, permanent pipe.
While slower than simply replacing the network all at once, this method will allow for constant,
uninterrupted use of the pipe network.
After installation of the new system is completed and the flow of waste has been transferred, the
remaining, unusable components of the old system can be disposed of in proper ways.
Location
Treatment systems that utilize bacteria to filter waste work best in hot climates (Mahmoud, Zeeman,
Gijzen, & Lettinga). With this fact in mind, we propose to build our new sewage treatment system near the
San Cristobal Airport. Lowland areas near the coast are generally warmer than areas in the highlands,
where the sewage treatment facilities are located now. Furthermore, building the facilities in closer to the
coast would eliminate the extra time required to pump sewage against the force of gravity into the
highlands and then back down into the ocean.

11. Materials
PVC tubes and Plexiglass are used for the digester and reactor (Mahmoud et. al). Also, wool sheets are
used to insulate the digesters in order to maintain constant temperature (Mahmoud et. al).
Funding
Implementing anaerobic digestion system will lead to a great amount of cost savings (Mahmoud et. al).
So, it could be assumed that implementing a combination of anaerobic and aerobic digestion would
contribute to a reduction in the overall percentage of budget for sewage treatment.

12. Sources:
Empresa Metropolitana de Alcantarillado y Agua Potable de Quito - EMAAP-Q. Normas de dise o ara
sistemas de alcantarillado para la EMAAP-Q. a edici n, M P-Q, Quito, 2009.
Pablo Daza, Ing. MSc. (2014).
.Puerto Baquerizo
Moreno, Provincia de Galapagos: Pablo Daza.
Ministerio del Ambiente. (2009). Analysis and monitoring of water quality in Santa Cruz, San Cristóbal,
and Isabela. Retrieved from
http://www.galapagospark.org/nophprg.php?page=desarrollo_sustentable_calidad _agua
Mike Alexander. (2013). Management Planning for Nature Conservation A Theoretical Basis & Practical
Guide. New York, London:Springer Dordrecht Heidelberg.