**3.2 Heterotrophic and total coliform count of sachet water samples**

Periodic analysis of sachet water is important to public health because millions of people in Nigeria consume it. An ideal situation would be to analyze every borehole water from which sachet water is produced to establish water treatment effectiveness. Enquiries made to sachet water producers for access to their source of water for production were not successful. To refuse access some companies gave information and advice that they do not have a borehole and their water for production is sourced from the supply by water tankers. Hence, commercial samples of sachet water were purchased from different locations with unknown source of initial water for production of sachet water on sale. Sixteen samples out of the 20 analyzed showed a NAFDAC product registration code, whereas 4 samples had no number or code indicating that they were not registered. The heterotrophic count was well within the limit for all samples analyzed, and coliform was detected in only two samples. Sample SC1c and SC3c had a coliform count of 2 Cfu/mL each (**Figure 2**).

## **3.3 Comparisons with WHO guidelines**

The WHO standards and guidelines are usually used to monitor water quality. The WHO categorizes drinking water systems based on population size and quality rating to prioritize actions. A quality score from A to D is awarded (quality decreases A to D) based on the proportion (%) of samples negative for *E. coli*. However, the samples under study were assessed for total coliforms and not *E.coli*; the scoring was carried out with the presumption that samples with high coliform count may contain *E. coli*. Total coliforms serve as a parameter to provide basic

#### **Figure 1.**

*Heterotrophic plate count of borehole water sourced from different areas of the community studied (C1–C4). The letters a to e represent different samples.*

**219**

management [35–38].

*4.1.1 Bacteria contamination of groundwater*

*Bacteriological Quality of Borehole and Sachet Water from a Community in Southeastern Nigeria*

information on water quality [23]. On this basis, the overall quality of borehole water in the community studied (all areas combined) was rated D (proportion of samples negative for coliform =13; 65%), whereas the sachet water was rated C

*Heterotrophic plate count of sachet water (S) sourced from different areas of the community studied (C1–C4).* 

Pathogenic bacteria often occur in borehole water systems especially in developing nations [24–26]. Coliforms found in this study and other Gram-negative bacteria have been isolated from boreholes in different parts of Nigeria by many investigators [27–34]. The organisms mentioned in these studies include *Enterobacter aerogenes*, *Escherichia coli*, *Klebsiella aerogenes*, *Klebsiella* sp., *Klebsiella pneumoniae*, *Klebsiella variicola*, *Proteus* sp., and *Proteus vulgaris*. Other bacteria isolated are *Providencia sneebia*, *Pseudomonas aeruginosa*, *Salmonella paratyphi*, *Salmonella* sp., *Salmonella typhi*, *Staphylococcus aureus*, and *Vibrio cholera*.

The prevalence of the aforementioned species and genera may be due to the classical microbiological methods used for isolation. In most cases, MacConkey media was used for *E.coli* and coliform identification with no molecular studies that included 16S or whole-genome sequencing essential for establishing the actual prevalent bacteria species and strains in boreholes. An opportunity exists for regular molecular characterization of bacteria found in boreholes to help differentiate between harmless coliforms, fecal coliforms, and the deadly *E. coli* strain O157: H7. Borehole operators are required to deliver safe and reliable drinking water to their customers. If a community consistently consumes contaminated water, they may become unwell. Hence, regular monitoring and assessment of borehole water sources help maintain quality and provide data on groundwater

In Africa, many people rely on water from a borehole, but the purity of the drinking water from this source remains questionable [39, 40]. The high heterotrophic count found in Area "2" of the community studied suggests that the groundwater of that area may be contaminated. The corresponding increased coliform count observed is consistent with the findings of Amanidaz et al. [41], which showed that

**4.1 Bacteria associated with boreholes in Nigeria**

*DOI: http://dx.doi.org/10.5772/intechopen.91812*

(18 = 90%).

**Figure 2.**

**4. Discussion**

*Letters a to e represent different samples.*

*Bacteriological Quality of Borehole and Sachet Water from a Community in Southeastern Nigeria DOI: http://dx.doi.org/10.5772/intechopen.91812*

**Figure 2.**

*Pathogenic Bacteria*

(**Figure 2**).

**3.3 Comparisons with WHO guidelines**

recommended heterotrophic limit [21]. All the other samples were below 500 Cfu/mL. Seven boreholes indicated the presence of coliforms because purple-pink colonies, which were 1–2 mm in diameter surrounded by a purple zone, were formed on the plates after incubation. Samples C2a, C2b, C2c, C2d, and C2e had coliform count of 17, 15, 9, 6, and 5 Cfu/mL, respectively, whereas samples C3b and C4b had coliform count of 4 and 2 Cfu/mL. The rest of the samples had no coliform on the plate used after incubation. A definitive trend was that samples with the highest

Periodic analysis of sachet water is important to public health because millions

The WHO standards and guidelines are usually used to monitor water quality. The WHO categorizes drinking water systems based on population size and quality rating to prioritize actions. A quality score from A to D is awarded (quality decreases A to D) based on the proportion (%) of samples negative for *E. coli*. However, the samples under study were assessed for total coliforms and not *E.coli*; the scoring was carried out with the presumption that samples with high coliform count may contain *E. coli*. Total coliforms serve as a parameter to provide basic

*Heterotrophic plate count of borehole water sourced from different areas of the community studied (C1–C4).* 

of people in Nigeria consume it. An ideal situation would be to analyze every borehole water from which sachet water is produced to establish water treatment effectiveness. Enquiries made to sachet water producers for access to their source of water for production were not successful. To refuse access some companies gave information and advice that they do not have a borehole and their water for production is sourced from the supply by water tankers. Hence, commercial samples of sachet water were purchased from different locations with unknown source of initial water for production of sachet water on sale. Sixteen samples out of the 20 analyzed showed a NAFDAC product registration code, whereas 4 samples had no number or code indicating that they were not registered. The heterotrophic count was well within the limit for all samples analyzed, and coliform was detected in only two samples. Sample SC1c and SC3c had a coliform count of 2 Cfu/mL each

heterotrophic count had the most coliform count (**Figure 1**).

**3.2 Heterotrophic and total coliform count of sachet water samples**

**218**

**Figure 1.**

*The letters a to e represent different samples.*

*Heterotrophic plate count of sachet water (S) sourced from different areas of the community studied (C1–C4). Letters a to e represent different samples.*

information on water quality [23]. On this basis, the overall quality of borehole water in the community studied (all areas combined) was rated D (proportion of samples negative for coliform =13; 65%), whereas the sachet water was rated C (18 = 90%).

#### **4. Discussion**

#### **4.1 Bacteria associated with boreholes in Nigeria**

Pathogenic bacteria often occur in borehole water systems especially in developing nations [24–26]. Coliforms found in this study and other Gram-negative bacteria have been isolated from boreholes in different parts of Nigeria by many investigators [27–34]. The organisms mentioned in these studies include *Enterobacter aerogenes*, *Escherichia coli*, *Klebsiella aerogenes*, *Klebsiella* sp., *Klebsiella pneumoniae*, *Klebsiella variicola*, *Proteus* sp., and *Proteus vulgaris*. Other bacteria isolated are *Providencia sneebia*, *Pseudomonas aeruginosa*, *Salmonella paratyphi*, *Salmonella* sp., *Salmonella typhi*, *Staphylococcus aureus*, and *Vibrio cholera*.

The prevalence of the aforementioned species and genera may be due to the classical microbiological methods used for isolation. In most cases, MacConkey media was used for *E.coli* and coliform identification with no molecular studies that included 16S or whole-genome sequencing essential for establishing the actual prevalent bacteria species and strains in boreholes. An opportunity exists for regular molecular characterization of bacteria found in boreholes to help differentiate between harmless coliforms, fecal coliforms, and the deadly *E. coli* strain O157: H7. Borehole operators are required to deliver safe and reliable drinking water to their customers. If a community consistently consumes contaminated water, they may become unwell. Hence, regular monitoring and assessment of borehole water sources help maintain quality and provide data on groundwater management [35–38].

#### *4.1.1 Bacteria contamination of groundwater*

In Africa, many people rely on water from a borehole, but the purity of the drinking water from this source remains questionable [39, 40]. The high heterotrophic count found in Area "2" of the community studied suggests that the groundwater of that area may be contaminated. The corresponding increased coliform count observed is consistent with the findings of Amanidaz et al. [41], which showed that

when the concentration of coliforms and fecal *Streptococci* bacteria increased in a water network system, there was also an increased concentration of heterotrophic bacteria. These contrasts with the work of others [42] where it was shown that high heterotrophic count inhibits coliform proliferation. Despite increased heterotrophic count and coliforms in the study of Amanidaz et al. [41], it was concluded that no correlation exists, and increased numbers could be due to variability in nutrient composition [43]. Another factor could be biofilm formation because it has been shown that attached bacteria in biofilms of a water system are more metabolically active than the ones that are free-living [44]. Groundwater is susceptible to contamination by both organic and inorganic contaminants [45–48]. Contamination could happen through natural processes, such as geological weathering and dissolution of numerous minerals beneath the earth's surface, which results in low natural concentrations of contaminants in groundwater [49]. Anthropogenic sources, such as seepages from agricultural wastewaters, domestic sewages, mining activities, and industrial effluents, can also affect the quality of groundwater in many parts of the world [50–52]. Other reports showed that borehole contamination may occur through domestic wastewater and livestock manure [53] industrialization and urbanization [54] and leakages from septic tanks [55] or pit latrines [56]. Seasonal environmental conditions may also contribute to increased bacteria count from borehole water because other investigators [57, 58] have demonstrated that higher bacterial count in borehole water occurs during the rainy season. This has been attributed to flooding which may allow floodwater to get into borehole systems that are not properly constructed.
