prepared by P. C. Ortega*, V. M. Valdez*, L. C. Balanon*, F. G. Decena*, R. D. Medrano*, E. Estillore* & C. H. Jucutan* *City of San Fernando, La Union, Philippines for Decentralized Wastewater Treatment Systems (DEWATS) for Urban Environments in Asia, 25-28 May 2011, Manila, Philippines. organized by International Water Association (IWA).
Suplemen HUD Magz Edisi 5 /2015. Kota BATAM Menyongsong MEA 2015
San Fernando's slaughterhouse wastewater treatment
1. Decentralized wastewater treatment systems for the Slaughterhouse
of the City of San Fernando, La Union
P. C. Ortega*, V. M. Valdez*, L. C. Balanon*, F. G. Decena*, R. D. Medrano*, E. Estillore* & C. H.
Jucutan*
*City of San Fernando, La Union, Philippines
Abstract:
The planning, implementation and operation of the City of San Fernando’s Slaughterhouse
Wastewater Treatment Facility provides many lessons on the benefits and challenges of
implementing Decentralized Wastewater Treatment Systems (DEWATS). Through the
implementation of this system and others like it, San Fernando is achieving its vision of becoming
a center of innovative wastewater technologies. The wastewater treatment facility at the
slaughterhouse was conceived because of the insufficient treatment being conducted previously,
consisting of a one-chambered septic tank and an open lagoon. The newly constructed
DEWATS, developed in cooperation with BNS-BORDA and funded by the Congressional
Development Fund (CDF) of Congressman Victor. F. Ortega, began operation in January 2011. It
has significantly improved the quality of the effluent as well as eliminating odours, containing all
wastewater underground, and creating an aesthetically pleasing area. The exemplary case of the
San Fernando City Slaughterhouse illustrates the obligatory need but also benefits of investing in
wastewater treatment infrastructure.
Keywords: environmental sanitation; slaughterhouse; decentralized wastewater treatment system
INTRODUCTION
San Fernando, La Union is a city of 120,850 located on the South China Sea about 270
km north of Manila. It is a regional hub for travel, trade, and governance. It is also a city
that is committed to sustainability. A number of environmental projects have been
embarked upon in San Fernando, in areas of solid waste management, coastal
resource management, forest resource management, and wastewater management.
While all these projects are important for the health of San Fernando’s citizens and its
environment, sanitation emerges as a key issue which the city has committed to
address through a variety of means.
Against this political backdrop, the issue of San Fernando’s slaughterhouse emerged.
The slaughterhouse suffered from poor wastewater treatment, leading to bad odors and
contaminated groundwater. In a collaborative effort, the City implemented a new
wastewater treatment system - emphasizing efficiency and environmental sustainability
through their planning. The completed system, while faced with several unresolved
problems, can easily be considered a success for San Fernando’s innovative
wastewater treatment planning process. Further, its slaughterhouse wastewater
2. management serves as an informative example for other cities seeking to implement
effective decentralized wastewater management systems.
CITY OF SAN FERNANDO: BACKGROUND
The City of San Fernando's commitment to wastewater management began with the
vision of former Mayor Mary Jane Ortega - in office from 1998-2007 - and has continued
under the leadership of the current Mayor, Pablo C. Oretga. The city's increasing
number of sanitation projects are beginning to draw attention to the city from other
areas in the Philippines and around the world. San Fernando aims to be a center for
diversified wastewater technology. By piloting a variety of wastewater treatment options,
San Fernando will be able to learn which function best for itself, as well as providing a
convenient location for study tours for other LGUs.
In 2005, this vision produced its first pilot project, in the form of ecological sanitation
(eco san) toilets, in one coastal and one mountainous barangay. Eco san is a waterless
technology that relies on separating urine and faeces so that they can be processed
separately. In 2006-2007, the Fisherman's village, a public housing project to relocate
marginalized people living in vulnerable coastal areas, was outfitted with 86 eco-san
toilet units. This initiative was spearheaded by a city partnership with the Center for
Advanced Philippine Studies.
San Fernando continued its innovative sanitation projects with a hybrid anaerobic and
aerobic waste water treatment plant for the city public market in 2006, in partnership
with USAID. The city is also currently in the process of installing Eco-Tanks, small scale
sewerage treatment facilities that collect wastewater into a tank to be purified, in
partnership with CityNet, USAID, and Rotary International. One tank is already installed
and operational, and plans are well under way for installation in two more barangays.
Finally, the construction of a Septage Treatment Facility has begun in 2011. This will
allow the implementation of septic tank desludging for all households and commercial
establishments in San Fernando.
Among all these sanitation projects, the decentralized waste water treatment facility at
the slaughterhouse stands out as project that took a poorly functioning waste water
treatment facility and transformed it into a cleaner, more aesthetically pleasing, and
easier to maintain system. It uses a different technology than that of the market waste
water treatment facility, requiring very little maintenance because the process is non-
mechanized. The city believes that projects like these are important, especially in light
of the current initiative to begin having residents pay a waste water management fee: by
focusing on city-owned generators of highly contaminated waste water, the government
demonstrates its own commitment and encourages the commitment of its residents.
3. THE SLAUGHTERHOUSE
The slaughterhouse in San Fernando was built in 2000, after moving from its previous
location near the city market (actually the current location of the market wastewater
treatment facility). It is owned by the city government and is located in Barangay Tanqui.
Around the property lies a creek to the East, an elementary school to the South, and
rice fields to the North and West. A police station is also nearby. The slaughterhouse
processes 80 hogs, 6 cattle, 2 carabao, and 10 goats daily. The meat from the
slaughterhouse is transported to the city market, where it has the potential to reach any
of the city’s more than 120,000 residents. Meat production is highly sensitive to
contamination by germs and bacteria. From the cleaning of animals both before and
after the slaughtering process, the slaughterhouse produces between 12 to 13 cubic
meters of wastewater per day. Wastewater discharged from a slaughterhouse has a
complex composition and is harmful to the environment; it is much stronger than
domestic or municipal wastewater. After an initial screening of coarse solids,
slaughterhouse wastewater is mainly composed of diluted blood, fat, and suspended
solids and may also contain some manure. It is generally reddish brown to dark brown
in colour and can have an objectionable odour. If untreated wastewater is discharged to
creeks, rivers and streams, the wastewater contributes significant levels of biological
oxygen demand (BOD) and other nutrients which cause pollution to the body of water
(BORDA, 2010).
Because of these dangers, it was an obvious choice for the city to adopt a project to
properly treat the wastewater from the slaughterhouse. Several goals were
accomplished in the process: the demonstration of a new decentralized wastewater
technology, the improvement of the appearance and smell at the facility, ameliorating
the quality of the effluent being discharged to comply with current standards and
regulations, increasing the safety of the meat produced, and generally creating a
cleaner environment.
Slaughterhouse: Pre-DEWATS
Pre-renovation, the slaughterhouse wastewater treatment process consisted of a simple
process of sedimentation, percolation, evaporation and aeration, through a septic tank,
grease trap and open lagoon. Taken as a whole, the process lacked efficiency in
properly treating the wastewater and mitigating odors. Some wastewater was allowed to
seep into the ground, contaminating underground impoundments. The open lagoon
allowed wastewater to decompose uncovered, creating odors which affected the
surrounding community. The problems associated with open systems were further
exposed as jeepneys and tricycles were washed beside the lagoon, allowing oil and
grease to flow into the system, neither of which it was designed to handle. Further, the
effluent was allowed to flow, incompletely treated and untested, into a nearby creek.
The still-hazardous wastewater sat stagnantly during the dry season; sinking into the
ground and again contaminating the groundwater. Complaints of foul smells, dirty
surroundings, flies and untreated water are all symptomatic of a treatment process
which failed to close biological circles, thus falling short of sustainability in the ecological
or sociological sense of the word.
4. IMPLEMENTATION OF WASTEWATER TREATMENT
Implementation process: How did DEWATS come to the slaughterhouse?
After the construction of the waste water treatment facility at the market and the various
partnerships with the Center of Advanced Philippine Studies (CAPS) and USAID, the
City was inspired to take action on wastewater treatment at the slaughterhouse. City
representatives from a number of departments visited several other wastewater
treatment facilities in other cities in the Philippines, where the concept of DEWATS was
demonstrated. On April 17, 2007, government officials from San Fernando, led by
Mayor Mary Jane C. Ortega, attended a presentation by BNS-BORDA on DEWATS and
how it could be applied in San Fernando. A site visit to the slaughterhouse was
conducted after the presentation to determine if the technology proposed by BORDA
would be appropriate for the site. Since then, a decision was made to undertake the
project. However, construction was delayed due to the previously planned
improvements to the slaughterhouse and the challenge of locating proper funding. In the
end, the project was funded through the Congressional Development Fund (CDF) of
Congressman Victor F. Ortega. The construction of the wastewater treatment facility
took place from October to December 2010, and operation began in January 2011.
Description of technologies and treatment process
The completed wastewater treatment system at the slaughterhouse functions without
mechanization or chemical inputs. The wastewater enters the biogas digester, where
the digestion process produced methane gas. The accumulation of pressure from the
gas pushes the wastewater into the settler, baffle reactor and anaerobic filter. Here, the
wastewater is retained for a set period of time, to ensure proper water quality.
The biogas digester allows the elements of the wastewater to decompose into their
individual components, one of which is methane gas. The gas can subsequently be re-
used elsewhere in the slaughterhouse operation.
The baffle reactor consists of a series of chambers which mixes the wastewater with
sludge, thus aiding the process of bacterial digestion of the wastewater.
The anaerobic filter circulates wastewater past micro-organisms which consume the
hazardous BOD and ammonia contained within.
The gravel filter exposes the wastewater to the biological community associated with
the roots of the plants grown throughout it. Oxygen also reaches the wastewater
through the plant roots, aiding in its treatment.
Each individual element in the treatment process is designed to function in coordination
5. with the elements before and after it, thus increasing the efficiency of the whole. For
example, the anaerobic filter removes all solid particles, so that the gravel filter into
which the wastewater flows next does not become clogged, and is able to filter the
water with little maintenance. The gravel filter also allows wastewater to travel just 5cm
under the surface - a small design feature which eliminates odor entirely. The anaerobic
filter and biogas digester are similarly low maintenance, due to the carefully coordinated
flow of wastewater from one end of the system to the other; reaching each new element
where it can be treated most efficiently.
The wastewater treatment system, as previously constructed, was not adequate for the
amount of wastewater flowing through it. An essential component of the new plan,
therefore, was the scaling-up of the treatment facilities to match the quantity of
wastewater being sent from the slaughterhouse. The biogas digester, anaerobic baffle
reactor, anaerobic filter and planted gravel filter were all constructed at such a size as to
be well suited to manage the 12-13 cubic meters of wastewater that the slaughterhouse
produces daily. Having carefully measured the amount of wastewater before designing
the treatment technologies, the city was able to construct them in such a way that the
wastewater is treated on the most efficient scale, through the most efficient means
possible.
OPERATION: DECENTRALIZATION SUCCESSES AND REMAINING ISSUES
The underlying principles of the DEWATS system at the slaughterhouse are efficiency
and sustainability. With capital costs now invested, the sustainability of the new facility
is perhaps best exemplified in the fact that maintenance costs are now minimal. The
chemical and biological efficiency of the system allows for very simple maintenance, as
natural processes are allowed to occur in an unobtrusive manner. No odor is emitted
from the underground systems, nor from the gravel pit. The common complaints of
smells, dirty surroundings and flies are all alleviated by a design which does not expose
the wastewater to open air until it flows into the creek after treatment.
The passive system requires no electricity, and very little maintenance. Once a week,
the manholes above the baffle reactor need to be opened and the reactor inspected to
remove any scum or solid particles that may have accumulated. Large pieces of debris
also need to be filtered and disposed of as the wastewater exits the slaughterhouse and
enters the treatment gauntlet. By reducing the need for extensive maintenance, the City
of San Fernando has also saved the money that would have been necessary to pay for
more maintenance workers, in addition to the repair costs associated with active,
electrically-powered systems.
6. Remaining issues
Some issues remain in the sustainable treatment of the slaughterhouse wastewater.
The primary concern is that effluent is still not up to DENR Class C standards, indicating
problems somewhere along the way. However, as the City learns from continued
operation and management of the DEWATS system, they are confident that solutions
can be found for all these problems.
Plants in the gravel pit have not been growing as quickly as expected (and, in some
cases, are dying). The root systems of the plants were a key element in the filtration of
the water, and the lack of substantial root development may be one of the reasons why
the final effluent is not up to the required standards. Additionally, staff at the
slaughterhouse have been thus far unable to procure replacement plants, so as to bring
the wastewater into contact with oxygen, lessening the smell. The source of the plant
failure remains undetermined, an unknown which slaughterhouse officials hope to
rectify before bringing in new plants. There is some unused space between the gravel
pit and the creek which could have been used to expand the gravel pit, potentially
affecting the efficiency of the aerobic process. Frequent desludging of the
slaughterhouse septic tank has also been necessary - once in the first three months.
While wastewater is strained for large objects before entering the septic tanks, debris
items such as horns and hoofs are finding their way into the tanks, causing premature
buildups.
A collaborative process was instrumental in bringing the slaughterhouse project to
fruition, with many different stakeholders and government agencies providing input
during the planning process. This management configuration, while successful during
the planning stages, has recently led to some miscommunication in regards to
maintenance responsibilities (generally no more than one hour per day). Currently, the
City Environment and Natural Resources Office (CENRO) is conducting quarterly
monitoring of the effluent from the DEWATS. The results of the monitoring by CENRO
have produced recommendations for troubleshooting and maintenance. The City
Veterinarian Office has a claim to responsibility for maintenance and operation through
their on-site presence in managing the slaughterhouse, and the technical expertise of
the City Engineering Office makes it another potential candidate for leadership. Some of
this confusion can perhaps be expected, as the DEWATS operation is still in its initial
phase. Moving forward, the identification of clear roles for the various groups involved
will be important for troubleshooting and maintenance activities.
7. LESSONS LEARNED FOR DECENTRALIZED WASTEWATER MANAGEMENT AND
PLANNING
The wastewater treatment facility at the slaughterhouse has been in operation for less
than half a year. While implementation has not been without its hitches, without
question the new facility constitutes a vast improvement over the old one. Major lessons
include the importance of leadership, designing technologies to scale, and proper
planning so as to minimize the need for maintenance.
The successes of the new treatment system can largely be traced to a planning process
which took sustainability and efficiency into account, thus diminishing the need for
ongoing management as an important variable in continued high effluent quality.
Although some issues remain, the overall efficiency of the system is such that no new
staff had to be hired in order to run or maintain the treatment process. Existing staff
have thus far been capable of performing the occasional routine tasks necessary to the
continued efficiency of the system. Although long-term sustainability cannot yet be
empirically proven, it seems likely that most of the problems presented are not structural
in nature, and can be resolved through relatively minor changes to the system.
Leadership has also been a key factor in every stage of the planning and
implementation process. Without the vision of elected officials, San Fernando would
never have begun its journey to be a center of diverse sanitation technologies.
Committed public servants have been essential in overseeing the project from its
inception; they have demonstrated continued determination to resolve the problems,
both managerial and operational, that have come up during this process.
Decentralized technologies have worked well for San Fernando for many reasons. By
building a DEWATS specifically for the slaughterhouse, the system was able to address
the unique aspects of the wastewater coming from that facility, where a more
centralized system would not have been able to do so. There is also a much lower cost
in creating smaller facilities to treat specific needs. The decentralization of wastewater
treatment is what has allowed San Fernando to diversify its sanitation technologies and
thus become an example for other cities.
CONCLUSION
The City of San Fernando’s commitment to effective, sustainable sanitation has borne
fruit in the new slaughterhouse wastewater treatment facility. The approach is at once
forward-thinking and simple; a product of strong long-term planning. Efficient
wastewater treatment at the slaughterhouse site provides a decentralized solution to
what is otherwise a complex problem of attempting to manage the health of 120,000
people. San Fernando has learned from its extensive study of projects throughout the
8. Philippines, and through the numerous innovative sanitation projects piloted within San
Fernando itself. It is through these trials and observations that San Fernando has been
able to parse that which fits its particular needs in the unique circumstances of the
slaughterhouse, and to implement a solution tailored to the problem. San Fernando’s
slaughterhouse DEWATS stands as a legitimate success for appropriate and effective
systems.
References
BNS-BORDA (2009) Preliminary Concept of Decentralized Wastewater Treatment Systems for City Abattoir of San
Fernando, La Union. Quezon City, Philippines.
EMB-DENR (2005) DENR Administrative Order No. 2005-10 Implementing Rules and Regulations of the Philippine
Clean Water Act of 2004 (Republic Act No. 9275).