There are many problems associated with the discharge of wastewater from industries into water bodies. These problems can lead to environmental pollution which in turn leads to a variety of diseases and a decline in public health for both people and marine organisms.
With the awareness of this issue, the External Processing Zones Authority (EPZA)1 in partnership with Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ)2 in Tanzania contracted OpenMap Development Tanzania (OMDTZ)3 to lead the Effluent Discharge Mapping project and conduct a pilot project in the EPZA industrial zone in Dar es Salaam aiming to acquire the geographic locations of the industries and develop an effluent discharge database management system (DBMS) from this spatial data.
Together with the above data, additional relevant data for the industries were collected in the resident industries and these will be presented in an interactive web map while the list will also be available as an XLSX file.
The data generated will further act as a guide for environmental control and useful for managing wastewater and boreholes’ existence. This is obtained from the knowledge of registered and non-registered boreholes and those in operation or not. This data will not only help the EPZA and GIZ in controlling the effluent discharges but will act as a pilot for a broader scope and can also be used by the National Environment Management Council (NEMC) in Tanzania.
The team from OMDTZ prepared a survey form7 using Excel in an XLS format for collecting data in the field with the ODK Collect application. This form was created following a similar order to the questionnaire provided by GIZ and EPZA8 but with the addition of a geo-tagging. Followed by training of field mappers especially from EPZA and the Wami/Ruvu Basin Water Board (WRBWO) were trained on the installation of the ODK application and how to collect data using their Android phones. One of the trainings involved changing the default server to that of OMDTZ in order to make sure that all mappers have access to download and upload the EZPA_Effluent_Discharge_Mapping form created by the team and to give the quality assurance team a grant to clean the data.
A total of 16 industries, 23 discharge points, and 4 boreholes were mapped in the Effluent Discharge Mapping project. These industries include Amimza Limited, DZ Card (Africa) Limited, Dart Global Logistics Ltd, Tanzania Tooku Garment Co. Ltd (with seven units), Soman Agro Export Ltd, Quality Pulse Exporters lTD, Paper Craft International United, Tembo Agro Ltd, YIHAI KERRY – Hyseas Trading Ltd, I Steel One.
Other buildings – not specifically industries – such as EPZA head office, fire block, cafeteria, shop, and clinic were mapped as they were in the area of focus.
| Feature | Total number |
| Discharge points | 23 |
| Industries | 16 |
| Boreholes | 4 |
| Other buildings | 10 |
| TOTAL | 53 |
OMDTZ has prepared an interactive web-based-map for online visualization showing features collected in the project including industries’ and discharge locations, borehole