Can Sanitary Surveys Replace Water Quality Testing? Evidence from Kisii, Kenya

Abstract

Information about the quality of rural drinking water sources can be used to manage their safety and mitigate risks to health. Sanitary surveys, which are observational checklists to assess hazards present at water sources, are simpler to conduct than microbial tests. We assessed whether sanitary survey results were associated with measured indicator bacteria levels in rural drinking water sources in Kisii Central, Kenya. Overall, thermotolerant coliform (TTC) levels were high: all of the samples from the 20 tested dug wells, almost all (95%) of the samples from the 25 tested springs, and 61% of the samples from the 16 tested rainwater harvesting systems were contaminated with TTC. There were no significant associations between TTC levels and overall sanitary survey scores or their individual components. Contamination by TTC was associated with source type (dug wells and springs were more contaminated than rainwater systems). While sanitary surveys cannot be substituted for microbial water quality results in this context, they could be used to identify potential hazards and contribute to a comprehensive risk management approach.

Assessing Drinking Water Quality at the Point of Collection and within Household Storage Containers in the Hilly Rural Areas of Mid and Far-Western Nepal

“…This study also highlighted the fact that sanitary inspection results at the household level did not reliably predict microbial quality of stored water, as has been raised by other studies [21,34]. Instead, only one variable is significantly correlated with storage water quality (last paragraph in Section 3.2).…”

An Assessment of Inter-Observer Agreement in Water Source Classification and Sanitary Risk Observations

“…We graphically compared the distance to nearest latrine estimated by Observer A against those estimated by the remaining five observers, calculating Lin's concordance correlation coefficient and related statistics (Bradley and Blackwood 1989) for these estimates using the Stata version 15.0 concord and batplot utilities. For each source and observer, we calculated a percentage sanitary risk score as the number of hazards present as a proportion of those observed, following common practice in analysing such data (Howard et al 2003;Misati et al 2017;Okotto-Okotto et al 2015). We again computed Bland and Altman limits of agreement and related statistics for Observer A's records against those of each of the remaining five observers.…”

“…Our study found comparatively low inter-observer agreement in recording sanitary risk scores, which has several implications for practice and interpretation of previous studies. Several studies have reported no or weak correlation between sanitary risk scores and faecal indicator bacteria counts in source water samples (Ercumen et al 2017;Luby et al 2008;Misati et al 2017). There are several explanations for this, including cross-sectional testing of water quality at a single time point, which may miss transient contamination events, and the use of aggregate scores derived from equally weighted checklist items.…”

The public health significance of latrines discharging to groundwater used for drinking

“…Unfortunately, sanitary inspection scores have little ability to predict bacterial contamination of well water (e.g. Hoque 1998;Luby et al 2008;Ercumen et al 2017;Misati et al 2017). A possible explanation for this poor correlation is that the contents of the standard WHO sanitary inspection are necessary but not sufficient because it excludes factors such as well construction, the survival and growth of bacteria…”