prepared by J.M. Antonio* * City Planning and Development Office, City Government of Dumaguete, Philippines (E-mail: cpdodgte@gmail.com) for Urban Environments in Asia, 25-28 May 2011, Manila, Philippines. organized by International Water Association (IWA).

1. Dumaguete City Septage Management System
(IWA-7739)
J.M. Antonio*
* City Planning and Development Office, City Government of Dumaguete, Philippines
(E-mail: cpdodgte@gmail.com)
Abstract
The City of Dumaguete Septage Management System demonstrates what small cities with good
governance can do to protect their water groundwater resource through low cost and simple
technologies in the absence of a sewerage system The project, conceptualized in 2004, started with
situational analysis of local wastewater management issues, evaluating technical, financial and
management options and simultaneously implementing a community-based social preparation
program. To legitimize the proposed program, the city government adopted an ordinance
mandating the establishment of a city-wide septage management system with provisions on the
proper design, maintenance, regular desludging of septic tanks, treatment of septage and “user fee”
to recover capital and operating costs. The city government in cooperation with the local water
utility company utilized their own funds to build and operate the system. Operation started in May
2010 as the first locally initiated and funded city-wide septage management system in the
Philippines.
Keywords
Septage; low cost treatment systems; social preparation.
PROJECT RATIONALE
The City of Dumaguete is a small coastal city with a day-time population of about 300,000
located in Central Visayas Region, Philippines. The city is largely a center of commerce and
trade and a university town where local leadership and residents are strongly aware of
environmental issues and have, in the past, undertaken various environmental programs.
The Philippine Clean Water Act of 2004 mandates non-highly urbanized cities to establish
septage management systems if and when a sewerage system is not in place. The Clean Water
Act also provides that local government units may raise funds for the construction and operation
of septage systems through property taxes or enforcement of a service fee system. Dumaguete
City is one of the numerous cities in the Philippines without sewerage systems and uses septic
tanks for disposal and treatment of domestic, institutional, commercial and other wastewaters.
The situation is more critical in Dumaguete with has about 20,000 improperly designed and

2. maintained septic tanks and the existence of sixteen deep wells and about eight hundred shallow
wells supplying the water needs of the entire city.
PROJECT BACKGROUND
In 2003, Dumaguete City was chosen as one of the four pilot cities in the Philippines in the
USAID technical assistance project “Local Initiatives for Low Cost Wastewater Treatment”
(LINAW). The project’s objective was to assist cities develop short, medium and long-term
water quality management strategies and implement pilot low cost wastewater treatment projects.
In Dumaguete, the project implementation was started with the conduct of multi-sectoral
assessment and characterization of wastewaters and prioritization of possible interventions.
Strategies and treatment options were presented and evaluated in terms of technical, financial
viability and sustainability. An immediate community concern was the city’s public market
which was then discharging raw and partially treated wastewater to the sea. In 2007, the city
government using its own funds constructed a decentralized anaerobic baffled reactor to treat the
public market wastewater before discharge to the sea.
Another major health and environmental concern identified by the community was the thousands
of essentially unregulated septic tanks in the city. Most septic tanks in the city are not properly
designed, maintained or desludged regularly or septage treated prior to disposal. If and when the
septic tanks were desludged, septage were often disposed untreated into open fields, farmlands or
areas hidden to the public.
Considering the above situation, the city government in compliance with the Water Code of the
Philippines, enacted the city’s Septage Management Ordinance in January 2006. The Septage
Management System provides for the proper design, construction, regular desludging of septic
tanks, collection and transport of septage, biological treatment of septage, collection of “user
fees” to recover capital and operating costs and a management body. A series of information
campaign and social marketing program was conducted by the city government to inform the
public on the proposed septage ordinance, and more importantly, the imposition of a “user
service fee” of P2.00 per cubic meter of water consumed by household or establishments as an
“add-on” to the monthly water bill. As expected, there was strong opposition from officials of
the village the where the septage treatment facility was to be located. Their fears ranged from
aerial transfer of pathogens, structural failure of treatment facility, potential flooding,
sustainability with the change of political leadership, and the novelty of the system which had
not been tried in the country or by any local government unit. The city government obtained the
necessary regulatory permits from the Dept. of Environment and Natural Resources and the
Dept. of Health to operate the city’s septage management system and the treatment facility. The
treatment plant consists of a two septage receiving tanks or grit chambers, sludge drying bed,
three anaerobic ponds in series, one facultative pond, three maturation ponds in series, planted
gravel filter and a wetland.
In December 2008, the city government started constructing the septage treatment plant using its
own financial resources with the city’s planning and engineering staff managing the
construction. In July 2009, the city government entered into a contract with the Dumaguete City
Water District wherein the water utility company would share 50% of the capital and operating

3. costs of the septage management system and receive 50% of any net income from the system.
The memorandum stipulates that the water utility company would perform the actual desludging
and transport operations while the city government would operate the septage treatment facility.
OPERATION OF THE SEPTAGE MANGEMENT SYSTEM
The construction of the treatment facility was completed in May 2010 at a cost of P20 Million.
Seeding of the septage treatment plant started thereafter with four formerly used vacuum trucks
operating five days a week. Two additional vacuum trucks were acquired bringing the total cost
of six vacuum trucks to P5 Million. Full operation of desludging septic tanks, treatment and
collection of septage user fees began in July 2010. Although septage truck operators had
undergone trainings on operating desludging pumps and other ancillary equipment, an incident
where a wrong switch was hit resulted in equipment and vehicle damage. Other than this
incident, there were no other untoward incidents with the vacuum trucks.
Although six trucks were already in operation by October 2010, the 80 cubic meter daily design
septage input could not be achieved. A higher volumetric loading is possible and hence, more
vacuum trucks are needed. The septage treatment plant was designed for an influent BOD of
2,500 mg/l. However, the actual BOD into the anaerobic pond is much less as than 2,500 mg/l as
a great portion of organic material (settled solids) is retained in the septage receiving tank or grit
chamber. Six months after the start of operation, the sludge drying bed was full with no takers of
the dried sludge. Heavy rains in late 2010 compounded the problem. To this date, however, dried
sludge is collected by farmers as soil conditioners. There is a much higher content of suspended
solids (sand and soil) content in septage in as much as most of the septic tanks desludged are old
or have never been desludged for years or have no concrete flooring at all. Big business
establishments such as hotels and college dormitories will need to be desludged as often as once
every four to six months as their septage is very concentrated as shown by recent events and to
avoid shock loading the treatment plant.
The expected rodents and vermints have not shown up as treatment plant technicians have kept
the facility clean with trees and blooms planted around the two hectare facility. However, frogs
have discovered the waters of the facultative and maturation ponds and wetland – jumping into
the ponds, propagating million of tadpoles and dying as they could not jump out producing
obnoxious odors. An 18” low concrete wall has been built around one maturation ponds and
wetland to keep out the frogs. Similar walls are being built around the facultative and maturation
ponds and wetland. Fish are now thriving in the facultative and maturation ponds and wetland.
The second maturation pond was recently emptied to check leaks and to remove sediments. The
leaks on the walls have been sealed and the pond is now back on line. Presently, a retractable
roof for the sludge drying bed and an additional sludge drying bed are being designed for
construction in June 2011.
An analysis of the treatment plant effluent showed a BOD of 2 mg/l - a substantial decrease from
an influent of 2,500 mg/l. The anticipated negative reaction of the community to the septage
“user fee” has not materialized largely due to the massive information campaign during the
formulation of the septage ordinance and the social preparation program participated in by
various sectors of the community. The distinctly identifiable septage trucks moving around the
city have also convinced the community that the city and water utility company are doing their

4. job and the “user fee” system is reasonable and legitimate. Private desludging companies have
brought in septage to the city’s treatment facility and paid treatment fees. An adjacent local
government unit has also requested desludging and treatment services. The much-feared odor
from the treatment plant has not occurred at all and the persons who previously opposed the
treatment facility have visited the site and are now enlightened on the treatment process.
As of March 31, 2011, 2,842 houses, institutions and business establishments have been
desludged with a total volume of 12,225 cubic meters of septage collected and treated.
Additional vacuum trucks are needed if the goal of desludging all septic tanks every three to five
years is to be achieved. Almost forty groups from city and municipal governments and non-
government organizations have visited the treatment plant since July 2010 and made inquiries on
how to establish a septage management system. The achievements of the Dumaguete Septage
Management System have been realized largely due to the determination of the city’s local
government leaders in pursuing environmental goals, technical support from external agencies
such as USAID, massive information campaign, social preparation and a supportive community.
Dumaguete City recognizes the pioneering efforts of the late Mayor and Governor Agustin R.
Perdices who had the courage to invest in an innovative and pioneering program to protect the
city’s groundwater resource. The septage management system is not the final solution to the
city’s wastewater concerns but it will suffice until a sewerage system or decentralized
wastewater collection and treatment systems are in place.