Decentralized Wastewater Treatment Solutions, DEWATS, Borda

1. DEWATS |
Decentralized
Decentralized Wastewater
Treatment Solutions Wastewater
Treatment Solutions
Demand-based technical
solutions to reduce water-
pollution by small and medium
enterprises and settlements
in densely populated areas
Treatment Systems |
DEWATS Service Package
Developed and disseminated by
BORDA & BORDA BNS Network

2. About DEWATS The Challenge
DEWATS stands for “Decentra- • DEWATS applications provide are combined according to demand: The demand for reliable, efficient
lized Wastewater Treatment treatment for both, domestic and • Primary treatment: sedimentati- and low-cost wastewater treatment Common Wastewater Problems
Solutions”. DEWATS is rather a industrial sources on and floatation systems is increasing world wide within Small and Medium Enterprises
technical approach than merely • DEWATS applications provide • Secondary anaerobic treatment especially in densely populated
a technology package. treatment for organic waste- in fixed-bed reactors: baffled urban regions where adequate
water flows from 1-1000 m3 upstream reactors or anaerobic wastewater treatment systems do
DEWATS applications are based on per day filters not exist and uncontrolled discharge
the principle of low-maintenance • DEWATS applications are reliable, • Tertiary aerobic treatment of wastewater endangers environ-
since most important parts of the long lasting and tolerant towards in sub-surface flow filters mental health and water resources.
system work without technical ener- inflow fluctuation • Tertiary aerobic treatment Many Governments have passed Many SME are not able to pay high
gy inputs and cannot be switched off • DEWATS applications do not need in polishing ponds new environmental regulations sti- investment and maintenance costs
intentionally. sophisticated maintenance DEWATS applications are designed pulating that dischargers of waste- required for sophisticated waste-
DEWATS applications provide state- Without considering facilities for ne- and dimensioned in such a way that water such as small and medium water treatment system.
of-the-art-technology at affordable cessary chemical pre-treatment of treated water meets requirements enterprises and housing estates will
prices because all of the materials wastewater from industries, DEWATS stipulated in environmental laws and be held responsible for wastewater
used for construction are locally applications are based on four basic regulations. pollution and must therefore treat
available. technical treatment modules which wastewater adequately on-site
before it is discharged into the en-
vironment.
Appropriate Wastewater Treatment for SMEs Maintenance of sophisticated
wastewater treatment systems
Advantages of DEWATS technology Hence require high-skilled personnel.
• Providing treatment for domestic and industrial wastewater DEWATS technology is an effec-
• Low primary investment costs as no imports are needed tive, efficient and affordable
• Efficient treatment or daily wastewater flows up to 1000m3 wastewater treatment solution
• Modular design of all components for small and medium sized
• Tolerant towards inflow fluctuations enterprises (SME).
• Reliable and long-lasting construction design Due to lack of investment capital
• Expensive and sophisticated maintenance not required and technical knowledge SME
• Low maintenance costs often adapt non-effective low-cost
„solutions“.
Wastewater discharged by SME
1 2 often does not meet environmental
standards.
Main DEWATS-modules for phy-
sical and biological wastewater
treatment:
1. Settler
2. Anaerobic Baffled Reactor
3. Anaerobic Filter
4. Planted Gravel Filter
3 4

3. Demand Dissemination
For many small and medium enter- For these potential clients, BORDA systems, project planning, imple- To assure sustainable dissemination Project planning Quality Control
prises and housing estates, con- and its network of partner organi- mentation and quality control has of appropriate wastewater treatment Project planning includes technical All DEWATS systems constructed
ventional wastewater treatment sations started in 1994 to develop resulted in a significant increase of infrastructure in the long-term, a feasibility studies, detailed enginee- are designed and have a guarantee
systems are technically sophisticated reliable and cost-efficient waste- implementation capacity and disse- mere focus on technical aspects has ring designs and cost-estimates. to fullfill specified discharge stan-
and costly, often require high energy water treatment systems which mination of technical know-how. proven insufficient. dards. Effluent tests are conducted
inputs for operation and rely on could efficiently treat non-toxic The approach for implementation Project implementation at regular intervals.
sophisticated maintenance services organic wastewater according to Today, more than 1000 stakeholders of DEWATS projects includes not Service provision depends on prefe-
to ensure continuous operation. legal environmental standards. from the private sector, govern- simply the construction of hardware rences of clients and network-part- Research & Development
In most cases, such requirements Successful efforts to standardize ments and NGOs have been but a whole comprehensive set of ners and may include supervision of Continuous efforts are made by
are unsuitable for SME. main components of the DEWATS trained by the BORDA-Network to integrated measures such as: construction, contractor services or members of the DEWATS partner-
approach, such as multi-stakeholder facilitate dissemination, implemen- turn-key operation. To ensure high network to improve efficiency and
approach, modular design of tation and maintenance of DEWATS Information seminars and quality standards, major tasks are effectiveness of treatment systems.
workshops to introduce DEWATS always carried out by qualified ex-
to key-stakeholders perts.
Early information of key-stakehol-
ders is vital to ensure continuous Technical support and monitoring
support for programme on macro- Staff responsible for operation and
level. maintenance of DEWATS plants are
adequately trained by technical ex-
Co-financing of perts during the first year of opera-
demonstration projects tion.
Financial support during the start- Dome shaped anaerobic baffled
reactor for biogas recovery
up phase of a demonstration pro-
ject enhances the achievement of
desired results and impacts.
Sector specific
information-seminars
An early focus on specific priority-
sectors supports an exchange of
ideas between experts and potential
clients that have similar professio-
nal experiences.
Technical training
Long-term DEWATS experts facili-
DEWATS ensures state of the art system resulting in the sustainable tate comprehensive training pro-
treatment results at affordable
cost, low maintenance and limi- operation of more than 250 grammes for qualified staff of part-
ted space requirements DEWATS plants. The success of ner organisations and take on
DEWATS has fostered cooperations a supervisory role during first tech-
with numerous government depart- nical implementations.
ments, municipalities and inter-
national donor agencies to increase
capacities and technical implemen-
tations.

4. Good Practices
DEWATS for Hospitals DEWATS for Communities
Characteristics: Technical Solution: Characteristics:
• 250 beds with outpatient • Treatment system for 150 m3 • Open waste water lagoon within • Fully mixed digester
department wastewater/day community (fixed-dome biogas plant)
• untreated wastewater discharge • Sedimentation + anaerobic filter • 6 public toilets/6 bathrooms • Baffled reactor
into nearby stream + horizontal sandfilter + puri- for 500 people • Landscaping
• complaints of neighboring fication pond • Unwillingness of landlords to • rehabilitation of WW ditches
communities • Pumping chamber after upgrade sanitation infrastructure • MOU between NGO and
• limited funds anaerobic filter • Willingness to provide lagoon space CBO regarding maintenance
• limited technical skills of staff • Total construction cost: • Willingness of people to pay of Sanitation/DEWATS infra-
• sufficient space $ 50.0000 for use of proper sanitation structure
• Training of maintenance staff infrastructure
and 1 year guarantee • People willing to manage sani-
tation infrastructure
Technical Solution:
DEWATS for Agroindustries Laboratory Test Results
Characteristics: Technical Solution:
• More than 100 cattle slaughtered Separation of wastewater
per day components:
• Extreme fluctuation of waste • De-watering, sedimentation DEWATS Treatment Efficiency
water composition & floatation
• extremely high organic load Treatment system components: No Para- Unit Anlytical-Results Reduction
• limited space for construction • Screening meter Inlet Outlet [%]
near stream • Sedimentation
• unreliable responsibility and • Composting 1 Temp. °C 27 27 –
maintenance • fully-mixed digestion in biogas 2 pH – 7,6 7,3 4%
reactor 3 BOD 5 mg/l 290 53,6 83 %
• Anaerobic filter 4 COD mg/l 590 84 86 %
5 Phosphate mg/l 18,33 3,67 80 %
6 TSS mg/l 172 84 51 %
Effluent Quality during first
months of DEWATS operation 7 Ammonia mg/l 0,19 0,07 63 %
Source: Graha Asih Hospital Bali,
Anaerobic Filter + Horizontal Sandfilter + Purification Pond

5. Benefits of DEWATS
• Establishing of multi-stakeholder
networks to combat water
pollution
• Building up implementation
capacity on various levels
• Providing treatment for both,
domestic and industrial waste-
water at affordable price
• Fulfillment of discharge standards
and environmental laws
• Wastewater pollution reduced
by up to 90%
• Providing treatment for waste-
water flows up to 1000 m3 / day
• Reliable and long lasting appli-
cations
• Tolerant towards inflow and load
fluctuation
• Materials/ inputs used for
construction are locally available
• Minimal maintenance and long • Resource efficiency and non • Resource recovery through
de-sludging intervals dependence on energy wastewater re-use and biogas
• Low operation and maintenance generation
costs
DEWATS Service Packages
o Treatment Systems o Emergency Sanitation o Health Impact Assessment
o Community Based Sanitation o Sanitation for Prisons & Hygiene Education
o School Based Sanitation o Sanitation for Real Estates o Capacity Development
o Sanitation for Hospitals & Hotels o Sanitation Mapping o Standardisation
o Wastewater Treatment o Municipal Sludge Treatment o Research & Development
for Agro-Industry Plant
DEWATS – Decentralized Wastewater Treatment Solutions
Developed & disseminated by BORDA and over 20 BORDA BNS Network Partners in South and South East Asia & Southern Africa
Bremen Overseas Research and Development Association
BORDA Germany BORDA South East Asia BORDA South Asia BORDA SADC
Head Office Programme Office Indonesia Programme Office India Programme Office
fon: + 49 - 421-137 18
e-mail: office@borda-net.org fon: + 62 - 274 88 82 73 fon: + 91 - 80 41 52 75 54 fon: + 255 - 681204991
www.borda-net.org e-mail: yogya@borda-sea.org e-mail: bang@borda-sa.org e-mail: dar@borda-sadc.org