Drinking Water Audit Report in respect of audit carried out on 15/06/21 at Ennis Public Drinking Water Supply
The Ennis WTP serves a population of approximately 27,945 and produces 12,097m3/day. The Ennis WTP is operated on behalf of Irish Water by EPS Group under a Design Build Operate (DBO) contract. The plant operates 24 hours/day within its design capacity of 750m3/hr.
The Ennis PWS is supplied by the Drumcliff spring source which is located in a below ground concrete chamber approximately 4m to 5m deep, <1km from the plant. According to EPS, the raw water quality is generally consistent but is influenced by surface water following heavy rainfall. The abstraction rate on the day of the audit was 486.6m3/hr.
Disinfection of the Ennis public water supply is by chlorination using 14% sodium hypochlorite. Duty and standby chlorine dosing pumps are in place with automatic switchover in the event of pump failure.
Irish Water should consult with the HSE in relation to the plants inability to verify the Cryptosporidium barrier
Irish Water should review and implement turbidity alarms and shutdowns on the microfiltration unit to ensure that the plant operates in accordance with the EPA’s Water Treatment Manual: Filtration.
Irish Water should review the chlorine alarm settings to ensure that an alarm is triggered in the event of water being inadequately disinfected