About Solution

The problem(s)

  • Municipal sewer network is limited: Plans to extend network are no longer feasible in most urban areas in Tanzania.
  • Poor sanitation practices as a result of expensive sewage handling solutions.
  • Outbreak of diseases such as cholera, dysentery, typhoid, etc.
  • Rapid ecological damage: Eutrophication causing loss of beneficial aquatic organisms.

Size of the problem(s)

Only 4% of 6 million people living in Dar es salaam
Tanzania's capital city have access to sewer network. Source: Wikipedia. Only 10% of over 52,000 industries in Tanzania have onsite sewage treatment plants. 26,500 Tanzanians, including 18,500 children under 5 years die each year from diarrhea attributed to poor water and sanitation. Source: World BankThe solution: Scavenger

Scavenger is a low cost, onsite, biological sewage treatment plant. It is made of stabilization chambers with Vetiver grass planted on top of chambers. i.e. hydroponically. Scavenger has the ability to absorb up to 99% of toxic, heavy metals, chemical pollutants and organic pollutants from black and grey water.

Scavenger treats all types of sewage to meet any local and international discharge standard. Scavenger uses the Sun's (free) energy to treat sewage, operates freely, requires low maintenance and technical know how.


A typical customer is an industry owner or manager who's already paying for sewer emptying services. Market research suggests that 60% of over 52,000 industries in Tanzania pay for sewer emptying services at least once per month. other types of customers are owners of hotels, apartments, offices, schools and other buildings that can accommodate a large number of people.

How beneficiaries currently solve the problem(s)

The majority reply on sewer emptying. Those who can't afford illegally release sewage into the environment and water bodies.

Effects of how beneficiaries solve the problem(s)

  • Ecological damage: Sewage kills fish in rivers, distorts natural biodiversity and promotes extinction of species.
  • Outbreak of diseases: Some services providers and industries have a tendency of dumping effluent in unauthorized area and water bodies.
  • High running costs: Sewage emptying services are expensive. They charge $75
    $120 for just 15,000 liters of effluent.


  • Sewer emptying services: It simply involves emptying the septic tank and dumping sewage elsewhere.
  • Aerobic treatment plants: They force air into sewage to support aerobic bacteria who eventually treat effluent.
  • Anaerobic treatment plants: They employ bacteria who live in the absence of air to treat sewage.
  • Chemical treatment plants: They involve adding chemical doses that treat sewage.

Positioning or Value Proposition

  • Sewer emptying services: Comparatively Scavenger is very cost effective, environmental friendly and financially sustainable.
  • Aerobic treatment plants: Scavenger is very cost effective to purchase and adds no electricity bills during operation.
  • Anaerobic treatment plants: Scavenger requires low real estate foot print and cheaper to purchase.
  • Chemical treatment plants: Scavenger has lower running costs and environmental friendly.

Marketing Strategy

Primary customers are those who already pay for sewer emptying services. First, emptying trucks will be purchased in order to gain market access. Second, each customer landed, intending to use our emptying services shall be offered a 50% credit for amount paid. only if s/he is willing to commit to buy scavenger in 1 to 3 years.

The 50% credit will be considered as advance payment at the end of term. For example a customer using 10,000 liter sewer emptying services per week spends $80 x 54 weeks = $4,320 per year. A 10,000 liter Scavenger costs around $6,000. So in order to buy Scavenger that customer will have to pay us $3,000 as advance money in cash or use our sewer emptying services for 2 consecutive years.

Disclosure: On every trip sewer truck makes 40% from $80 thus $1,728 per year as profit. Building a 10,000 liters Scavenger costs us around $3,500. That's why the customer will use our sewer services for 2 years. Upon building Scavenger customer will start saving $80 every week. Thus will be required to repay $6,000 in 1.5 years.Before civil and building works begin special contract agreements shall be entered with customers to ensure they get to own Scavenger only if they pay their debts fully. We are also planning to work with a financial institution called EFTA. They will finance customers to help save time required to build sufficient credit with us.Business' benefits/value

The Business has unique potential consisting of;

  • A qualified and experienced team
  • Strategic planning
  • Trade secrets

Health, social and environmental benefits of Scavenger

  • Public health improvement: preventing sewage from polluting water bodies and causing illness.
  • Creation of jobs: Vetiver leaves
    a by-product of Scavenger
    are used as raw materials in construction, arts and crafts industries.
  • Encouraging savings: Reduction of running costs especially sewage emptying for industry owners and the general public.


Mr. Calistus Kavindi
Founder. BSc. in Biological and Environmental Sciences, wastewater expert and serial entrepreneur.

Key Advisors

  • Paul Truong (Vetiver Expert)
    Technical Advisor
  • Mzee Chilimali (Contractor)
    Technical Advisor
  • Stephen Holmes
    Business Development Advisor
  • Patrick Muwowo
    Financial Advisor


  • Have installed and commissioned one sewage treatment plant and have inquiries from potential customers.
  • Have a legal entity and business location.
  • Are in good relations with relevant stakeholders including government agencies.
  • Have a business plan, 5 years financial projections and business model.
  • Have secured a civil and building license.
  • Have employed 2 full time staffs.
  • In the process of securing relevant licenses for sewage business and training staff.

Scaling Plan

The business has spent 1 year to establish proof of concept using revenues from sales. In the next 2-3 years business is expected to prove its sustainability/profitability in the market by sales and grants revenues. In 5 years the business is expected to grow by revenues from sales, grants and loans. By year 6 to 10 the business is expected to scale throughout Tanzania and Africa using revenues from sales, private equity and loans.

Activity plan and budget

Development of the most cost effective working design of Scavenger namely Scavenger Plus. Budget: $20,000

  • Piloting, demonstrating and launching Scavenger Plus. Budget: $30,000
  • Support for certification activities. Budget: $10,000
  • Promotion and marketing activities. Budget: $50,000

Total funding requested: $110,000



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