Data on surface water bodies like rivers, dams, reservoirs, and related  flow characteristics, along with assessments for water risks, stress, and flood risk. 

freshwater

Freshwater

### Overview  
  
Untreated connected wastewater measures the percentage of domestic wastewater that is connected through a sewerage system and not treated to at least a primary treatment level. Higher values indicate higher percentages of point source wastewater discharged without treatment. These values were then converted into risk scores based on the thresholds defined in the methodology. These risk scores range from low (<30%) to extremely high (>100%).

  
  
Wastewater discharge without adequate treatment could expose water bodies, the general public, and ecosystems to pollutants such as pathogens and nutrients. The indicator compounds two crucial elements of wastewater management: connection and treatment. Low connection rates reflect households’ lack of access to public sewerage systems; the absence of at least primary treatment reflects a country’s lack of capacity infrastructure, institutional knowledge) to treat wastewater. Together these factors can indicate the level of a country’s current capacity to manage its domestic wastewater through two main pathways: extremely low connection rates (below 1 percent), and high connection rates with little treatment.  Values are available per country. 
  
  
### Methodology  
  
Sewerage connection and wastewater treatment data come from a white paper published by the International Food Policy Research Institute (IFPRI) and Veolia (Xie et al. 2016). In brief, Xie et al. aggregate three of the leading research papers on country-level connection and treatment rates into one data set through a hierarchical methodology. The data includes the percentage of households connected to sewerage systems (percent connected), and the percentage of wastewater connected left untreated (i.e., not treated using primary, secondary, or tertiary treatments) (percent untreated).  
  
The calculation is based on the Yale Environmental Performance Index’s Wastewater Treatment (WWT) indicator [(Wendling et al. 2018)](https://epi.envirocenter.yale.edu/node/36476). WWT examines the performance of wastewater treatment  [(Wendling et al. 2018)](https://epi.envirocenter.yale.edu/node/36476). The untreated, connected wastewater indicator reverses the WWT to instead examine the hazard.  
  
The first step in the calculation was to group all countries with a household sewage connection rate of less than 1% into the “Low to no wastewater connected” category.  
  
For all remaining countries, the percent of wastewater treated to at least primary treatment (100% - percent of untreated wastewater) was calculated. This was multiplied by the household connection rate to find the percent of treated connected wastewater. Next, the percent of treated connected wastewater was subtracted from 100% to find the percent of untreated connected wastewater. 
  
  
Finally, raw untreated connected wastewater values were converted to risk scores between 0 and 5, based on quantiles. These scores were placed into categories indicating how high the risk for this indicator is. The thresholds for raw untreated connected wastewater values and the corresponding risk scores that were used in each category are defined below as Risk Category (Risk Scores): Raw Value Thresholds.  
  
- Low (0-1): < 30%  
  
- Low to medium (1-2): 30 - 60%  
  
- Medium to high (2-3): 60 - 90%  
  
- High (3-4): 90 - 100%  
  
- Extremely high (4-5): 100%  
  
- Low to no wastewater (5): -1  
  
For the full documentation, please see the source [methodology](https://www.wri.org/publication/aqueduct-30).  
  
### Additional Information  
  
Resource Watch shows only a subset of the dataset. For access to the full dataset and additional information, click on the “Learn more” button.  
  
### Disclaimer  
  
Excerpts of this description page were taken from the source metadata.

International Food Policy Research Institute (IFPRI)

Untreated Connected Wastewater, Aqueduct 3.0

wat-058-aqueduct-untreated-connected-wastewater-rw

water-peace-security

Water, Peace & Security

2000 to 2010 Untreated Connected Wastewater

Measures the percentage of domestic wastewater that is connected through a sewerage system and not treated to at least a primary treatment level

Water, Peace & Security

Aqueduct Untreated Connected Wastewater

2000 to 2010 Untreated Connected Wastewater