Single & Multi-Story Houses
Odor-free, maintenance-free treatment for family homes, with no gully bowser visits to arrange.
Get a Quote 2018 Presidential Innovation Award Winner
10-Year Written Warranty
Sri Lanka's Premier Parawewa Bio Septic System
“පරවැව ක්රමය” - පරිසරය රකින වැසිකිළි වල ක්රමය
A patented Parawewa system with two options: Option A (gravity-fed, no electricity) and Option B (Seal Type Parawewa System for high water tables). No gully bowser emptying.
Real installation photo
From a Parawewa site in Sri Lanka
1996
Invented in Sri Lanka
#16371
Sri Lanka Patent
10 Years
Written Warranty
ENGINEERED SYSTEM OPTIONS
Two Custom Parawewa System Options
Parawewa provides two engineered models tailored for Sri Lanka's diverse soil & water table conditions.
OPTION A • STANDARD GROUND
100% Gravity-Fed Model
100% Passive Flow • No Electricity • No Moving Parts
Ideal for standard inland building plots with normal soil elevation and standard ground water levels. Uses natural gravity head pressure to pass effluent through biological filter media.
- No Electricity Usage (No power bill additions)
- 100% Operational During Power Cuts
- No Mechanical Parts to Service or Replace
- Industry's Best 10-Year Written Warranty for Parawewa Sewerage System
OPTION B • HIGH WATER TABLE
Seal Type Parawewa System
Water-Sealed System • Flood-Proof
Engineered specifically for high groundwater table lands, marshy wetlands (Negombo, Wattala, Ja-Ela), coastal properties, and flat elevations where gravity discharge is impossible.
- Heavy-Duty Submersible Effluent Pump
- Prevents Groundwater Flood Infiltration
- Treated Water Soaks Safely into the Ground
- Industry's Best 10-Year Written Warranty for Parawewa Sewerage System
For your information: which Parawewa system is built
| System | Low groundwater level | High groundwater level |
|---|---|---|
| Toilet Parawewa system | Standard Parawewa system (Option A) | Water-sealed Parawewa system (Option B: Seal Type) |
| Wastewater Parawewa system | Standard Parawewa system (Option A) | Water-sealed Parawewa system (Option B: Seal Type) |
In every Parawewa system, the water is treated to a level fit for absorption and then soaks into the ground. Only the water-sealed system uses a pump, and it uses less electricity than other sewage treatment plants.
CORE ADVANTAGES
Why Should You Choose Parawewa?
Choosing the right sanitation system is crucial for your property's longevity and environmental safety. Here is why homeowners and businesses across Sri Lanka rely on Parawewa Bio-Septic Systems.
1. 100% Water-Tight & Monsoon Proof
Engineered to prevent groundwater infiltration during heavy Sri Lankan rains and to stop toxic wastewater seeping into the surrounding soil and wells.
2. Industry's Best 10-Year Written Warranty
Maintenance-free tanks, backed by an official 10-year written warranty issued directly by Parawewa.
3. No Gully Bowser Hassle
Natural bio-filter technology: multi-stage aerobic digestion breaks down organic matter and reduces odour, so no desludging and no gully bowser are needed.
4. Presidential Awarded Tech
- Invented under Sri Lanka Patent #16371
- Winning 1st Place at the 2018 Presidential Innovation Awards
- iCAN Canada 2019
5. Engineered for High Water Tables
Specially weighted and reinforced concrete structures resist flotation and cracking in low-lying and flood-prone areas, with Option B, the Seal Type Parawewa System, for high water tables.
6. Rapid Islandwide Installation
Built on site under strict quality control, with turnkey excavation, installation and backfilling by our own team, across Sri Lanka.
HOW THE SYSTEM IS BUILT
Where the System Sits and How It Is Built
Illustrations of where a Parawewa chamber sits beside the building and how it is constructed before it is covered.
These illustrations are conceptual. Tank type, size and layout vary by site and are confirmed at your free site inspection.
TARGET APPLICATION SUITES
Who Does Parawewa Suit?
Engineered to serve single residential homes up to large commercial complexes across Sri Lanka.
High Water Table Land
For waterlogged and coastal land in areas such as Negombo, Ja-Ela, Wattala and Mathugama.
Get a QuoteOffices & Commercial Buildings
For offices, banks and retail outlets that need reliable, CEA-compliant wastewater treatment.
Get a QuoteHotels & Resorts
Odor-free treatment near guest areas for hotels and eco-resorts in Bentota, Ella and Sigiriya.
Get a QuoteHousing Schemes & Developers
One reliable, warranted system for every unit in a new housing scheme or apartment project.
Get a QuoteFactories & Industry
High-capacity treatment for factory canteens, staff quarters and busy production sites.
Get a QuoteSchools, Hospitals & Government Institutions
For schools, education centres, hospitals and government institutions with many daily users.
Get a QuoteHAPPY CUSTOMERS
Trusted by factories, hospitals, schools, hotels and homes across Sri Lanka
Nithya Papers & Board Lanka (Pvt) Ltd – BOI Zone, Horana
JSW Apparels (Pvt) Ltd – Panadura
MAGA Engineering (Pvt) Ltd – KMTT Project, Ampitiya
Cisco Speciality Packaging (Pvt) Ltd
Lanka Precision Engineering (Pvt) Ltd – Mulleriyawa
Ethimale Plantation – Siyambalanduwa, Monaragala
WP/JP/ Kottawa Dharmapala Maha Vidyalaya
Commercial Credit – Kiribathgoda
Access Engineering – Port of Colombo
Wish Fertility Hospital – Maharagama
Elastomeric Engineering Co. Ltd – Horana
LOTEK (Pvt) Ltd
David Pieris Holdings (Pvt) Ltd – GLO Camp, Welikanda
Jaykay Marketing Services (Pvt) Ltd – Keells
ITD Cementation India Limited – Port of Colombo
Lanka Tiles – Ranala
Gislaved Gummi Lanka (Pvt) Ltd – Bokundara
Atire (Pvt) Ltd
Roo Mansala Boutique Villa – Sigiriya
Also trusted by
- Western Provincial Council – Ayurvedic Hospital, Weediyagoda
- Western Provincial Council – Ayurvedic Hospital, Jamburaliya, Kesbewa
- Sabaragamuwa Provincial Council
- Methodist College – Rawathawatta, Moratuwa
- Apartment Complex – Kohuwala
- Housing Scheme – Bokundara
FEATURED KNOWLEDGE ARTICLES
Engineering Insights & Guides
Top-rated environmental engineering articles. Tap any article to read the full guide.
WATER SAFETY
5 Signs Your Septic Tank is Leaking Groundwater in Sri Lanka
Learn how to detect groundwater leaks during monsoon season and how sealed Parawewa bio tanks protect your drinking water.
COST SAVINGS
Parawewa vs. Mechanical STPs: Option A Gravity vs Option B Seal Type
Compare 24/7 electric air blower running costs against Option A 100% passive gravity flow and Option B: Seal Type Parawewa System.
HIGH WATER TABLE LANDS
Installing Bio Septic Tanks in High Water Table Lands (Ja-Ela, Mathugama & Coastal)
Step-by-step engineering guide for installing leak-proof bio septic systems in coastal and marshy soils like Ja-Ela, Mathugama and Negombo.
BUSINESS VIDEOS
Parawewa Videos
Watch videos about the Parawewa system, how it works and who is using it, on YouTube.
OFFICIAL DEMONSTRATION VIDEO
PARAWAWA SEWAGE SYSTEM - වෙනස්ම විදිහට වැසිලකිළි වලක්
Official Sri Lanka feature showcase explaining how Parawewa biological filtration decomposes sewage without odor or emptying.
VIDEO BY NILAME
ගෙදර ටොයිලට් වල මේ විදියට හදන්න අවුරුදු 100 ක් ගියත් පිරිනේ නෑ - Sewage Treatment System | පරවැව
A walkthrough of the Parawewa sewage treatment system for household toilets.
VIDEO BY SRI LANKA INVENTORS
Environment Friendly Septic Tank
The Parawewa septic tank system presented by Sri Lanka Inventors.
ENGINEERING COMPARISON
Parawewa vs Mechanical Sewage Treatment Plants (STP)
Compare our patented biological system (Option A & Option B) against imported mechanical STPs, existing competition, and traditional concrete pits.
| Feature / Parameter | Parawewa | Imported Mechanical STP (Aerated) | Traditional Concrete Septic Tank |
|---|---|---|---|
| System Options | Option A (Gravity) or Option B (Seal Type Parawewa System) | Single Fixed Electric Blower Unit | Standard Concrete Ring Pit |
| Electricity Required | Option A: No Electricity / Option B: low electricity use | Requires 24/7 Electric Blower (High Bills) | No Electricity |
| Power Cut Operation | Option A operates 100% during power cuts | Blower Stops; Bacteria Dies & Odor Spills | Operates (Overflow Risk) |
| Manufacturer Warranty | 10-Year Written Guarantee | Limited 1 - 3 Year Warranty | No Warranty |
| Gully Bowser Emptying | Never Required (No Gully Fees) | Periodic Sludge Purging Required | 1-2 Times Per Year (Costly) |
Also comparing an aerated package plant? Read the Parawewa vs Aerated Package Plants comparison
REAL PROJECT CASE STUDIES
Where Parawewa Is Installed
Verified factory, retail, and residential installations across Sri Lanka — real projects and locations, not marketing quotes.
VERIFIED INSTALLATION
Industrial paper manufacturing facility installed with a Parawewa system engineered for high daily wastewater volume and ongoing CEA discharge compliance — removing the need for periodic gully bowser servicing at an active production site.
VERIFIED INSTALLATION
A garment manufacturing plant with significant daily staff occupancy runs on a maintenance-free Parawewa installation, avoiding disruption to factory operations from recurring suction-truck visits.
VERIFIED INSTALLATION
A high-footfall retail supermarket outlet uses Option A's no-electricity design, avoiding the recurring blower running cost that a mechanical STP would otherwise add to daily overheads.
VERIFIED INSTALLATION
A multi-unit housing scheme in Parawewa's own home district was fitted with Parawewa systems, avoiding a shared gully bowser maintenance burden across every household in the development.
ABOUT PARAWEWA
About Parawewa Septic Systems
Pioneering sustainable environmental engineering in Sri Lanka since 1996.
At Parawewa, we are dedicated to transforming wastewater management across Sri Lanka through advanced patented engineering and eco-friendly, locally developed bio-septic technologies. Founded on the principle of delivering durable, hassle-free sanitation solutions, Parawewa replaces traditional, slow-to-build brick-and-mortar septic pits with precision-built, leak-proof in-situ cast concrete systems designed to last for generations.
Who We Are
Parawewa is a Sri Lanka-based leader in wastewater solutions. Our engineering combines heavy-duty concrete construction with natural, multi-stage biological treatment. Whether you are building a modern home, developing a commercial property, or upgrading existing sanitation infrastructure, our team delivers seamless end-to-end installation with minimal disruption to your land.
Invented in 1996 and protected under Sri Lanka Patent #16371, the Parawewa bio septic system won 1st Place at the 2018 Presidential Innovation Awards in Sri Lanka and a Silver Medal at iCAN 2019 in Canada.
What Sets Us Apart
Rapid Installation
Our units are built on site under strict quality control standards, enabling rapid site placement and setup.
Eco-Friendly Bio-Treatment
Multi-stage aerobic digestion naturally breaks down waste, producing cleaner effluent and protecting Sri Lanka’s soil and groundwater.
100% Water-Tight & Durable
Built to withstand high groundwater pressure, heavy monsoon conditions and soil shifts without cracking or leaking.
Cost-Effective & Maintenance-Free
Engineered to prevent blockages, with no desludging and no gully bowsers needed, saving long-term maintenance costs.
Our Core Services
Residential Bio-Septic Tanks
Custom-sized in-situ cast units engineered for single-family homes and apartment units.
Commercial Sanitation Systems
High-capacity bio-septic and holding solutions for hotels, restaurants, factories and schools.
Full Site Preparation & Installation
Turnkey excavation, positioning, connection and backfilling, handled entirely by our skilled team.
Inspection & Maintenance Support
Ongoing technical consultations, system health checks and routine operational support.
Our Mission & Promise
Our Mission: To deliver safe, reliable and environmentally friendly sanitation solutions to every Sri Lankan household and business while preserving our island's soil and natural waterways.
We take pride in offering transparent unit pricing, clear installation timelines, and dedicated after-sales support for every project we undertake.
Meet the team
AUTHENTIC DOCUMENTS & CERTIFICATES
Official Awards & Patent Gallery
Real document photographs downloaded directly from parawewa.lk official archives.
PRESIDENTIAL AWARD 2018
1st Place New Innovation
Official Presidential innovation certificate awarded by the President of Sri Lanka.
INTERNATIONAL ICAN CANADA 2019
Silver Medal Innovation Award
Awarded in Toronto, Canada for international eco-technology excellence.
SRI LANKA PATENT #16371
Official Government Patent
Original patent registration document for biological filtration.
CEA WATER QUALITY COMPLIANCE
Laboratory Test Report
Independent laboratory test report on the treated water quality.
INTERACTIVE ESTIMATOR
Calculate Your Tank Capacity
Select your building type and estimated number of users to see the recommended Parawewa tank capacity.
Input Property Details
Recommended Tank Capacity
1,500 Liters
Wastewater Treated per Year
273,750 L / yr
Disclaimer Note for General Public: This calculator provides an approximate capacity estimate for preliminary public guidance only. For detailed civil engineering design and custom commercial site specifications, please contact Parawewa.
FREQUENTLY ASKED QUESTIONS
Common Questions & Answers
Find immediate technical answers about Parawewa eco bio septic tank systems.
How does Parawewa compare to imported mechanical STPs in Sri Lanka?
Unlike imported mechanical STPs which require continuous 24/7 electricity to run air blowers and need frequent mechanical servicing, Parawewa engineered by Parawewa provides two flexible options: Option A (100% Gravity-Fed with no electricity for normal ground) and Option B (Seal Type Parawewa System for high ground water table), both featuring a 10-Year written manufacturer guarantee and no gully bowser emptying.
What is the difference between Option A (Gravity) and Option B (Seal Type Parawewa System)?
Option A (Gravity-Fed) operates on 100% passive natural gravity flow with no electricity, ideal for standard ground levels. Option B (Seal Type Parawewa System) is a water-sealed system designed specifically for high water table lands (such as Negombo, Ja-Ela, Wattala or Mathugama) where natural gravity discharge is restricted. It uses some electricity, but less than mechanical STPs.
How does the 10-Year Manufacturer Warranty work?
Parawewa issues an official 10-Year written manufacturer guarantee certificate covering structural tank integrity, chamber sealing, and multi-stage biological layer filtration performance.
Can Parawewa be installed in high water table and marshy lands?
Yes! Parawewa Option B is specifically engineered for high groundwater tables, wetlands, and coastal soils (Negombo, Ja-Ela, Wattala, Mathugama, Galle). The hermetically sealed concrete body prevents inward water seepage and flood backflow.
Does Parawewa comply with Central Environmental Authority (CEA) standards?
Yes, Parawewa effluent discharge is laboratory-tested to meet all Sri Lanka Central Environmental Authority (CEA) discharge guidelines (BOD & COD limits), making it suitable for commercial buildings, hotels, and apartments.
Who is the owner and inventor of Parawewa?
The Parawewa bio septic system was invented in 1996 by Ranjith Dharmakeerthi Mannage, Managing Director of Parawewa in Sri Lanka. The technology holds Sri Lanka Patent #16371.
What size Parawewa tank does my property need?
Recommended capacity depends on your property type and number of occupants. Use our interactive tank sizer above for an instant approximate estimate, then request a free site inspection from Parawewa for an exact recommendation and quote.
Is Parawewa suitable for factories, hotels, and commercial buildings, or only homes?
Both. Parawewa is installed across residential, industrial, and commercial sites islandwide — including factories, retail outlets, and housing developments — with capacity sized to each site's occupancy and wastewater load. See our real project case studies for examples.
GET IN TOUCH / සම්බන්ධ වන්න
Request a Free Site Inspection & Quote
Our expert engineering team at Parawewa led by founder Ranjith Dharmakeerthi Mannage is ready to assess your site anywhere in Sri Lanka.
Head Office Contact Info
Parawewa
Managing Director: Ranjith Dharmakeerthi Mannage
Official Head Office Address
143/2 Kesbewa Kindelpitiya, Bandaragama Rd, Piliyandala 10300, Sri Lanka
Direct Hotlines
074 060 4936 /
0112 703 619
WhatsApp Support
+94 74 060 4936 (Click to Chat)
Email Consultation
info@parawawa.lk