Atención temporal a la población migrante:

By referring to two maintenance programs, one from the UK and the other from the USA, similarities in maintenance practices could be identified. The comparison of these two O&M regimes will serve as an example of international maintenance regimes, which can be compared to local regimes. Comparing local practices to international norms may highlight any potential differences. Should a difference in practices be identified and be applicable to the maintenance of local structures, it can be incorporated into the study and aid in the development of a prioritization method. Focus is placed on the inspection, deterioration identification, condition assessment and maintenance activities of these regimes, as they adhere to the approach taken by bridge and pavement management systems. The following sections provide a brief overview of international WRS maintenance regimes.

Inspection

The WSAs should have detailed records of the location of the service reservoirs along with detailed construction drawings if possible [EPA, 2011]. The detailed records should also include a log of previous inspection and cleaning activities. This information will aid the inspector in determining the severity of the identified issues.

A qualified inspector should perform the inspection of a service reservoir [RCSA,

2009]. The term qualified inspector may include the following [RCSA, 2009]:

• American Petroleum Institute (API) API 653 Certified tank inspector. • NACE International Certified Coating Inspector.

• A Professional engineer with documented experience with atmospheric tanks. • A Certified operator with documented experience with atmospheric tanks.

It should be noted that these qualified inspectors do not necessarily relate to concrete reservoir inspections.

Before an internal inspection can be conducted, the inspector should perform a perimeter investigation if possible [EPA, 2011]. The objective of the perimeter

investigation is to ascertain the susceptibility of the facility for contamination. A detailed inspection of the fixtures associated with the reservoir must be conducted to ensure the reservoir is protected from contamination [RCSA, 2009]. Investi- gation of the vents, overflows and access hatches are the most critical [RCSA,

2009].

An exterior inspection is performed to assess the structural integrity of the reser- voir and may include any signs of structural defects and weaknesses. Identification of corrosion, cracks, holes, deterioration of paint/exterior coating and any signs of wear is done. The severity of the external deterioration may indicate the condition of the structural integrity.

Once the external inspection is completed, an internal inspection may take place. There are three general options for the internal inspection of service reservoirs [EPA, 2011]:

• Fully drain the reservoir to allow inspector access (this may not always be an option, as the reservoir may be unable to be taken out of service for a period of time, due to water restrictions).

• Use certified SCUBA divers to perform a submerged inspection. • Use remotely operated vehicles (ROV) to inspect and clean reservoirs. The first option is the most popular method and is also most preferable as it allows for the most thorough cleaning of the reservoir [EPA, 2011]. If the WSAs decide to employ this method, notification to consumers should be done well in advance. The interior of the reservoir should be inspected for corrosion, cracks, holes, pitting and any signs of deterioration that may cause contamination and loss of structural integrity [RCSA,2009]. To check for water ingress through the roof, it is suggested that a roof flood test be performed [EPA,2011]. The test is performed by flooding the roof area suspected of cracking and monitoring any signs of ingress [EPA,

2011]. Specific attention should be given to the joints and waterproofing of concrete reservoirs [RCSA, 2009].

The interior inspection must include an evaluation of the valve performance [EPA,

2011]. All associated valves and internal access components must be inspected for deterioration, specifically rust damage, and be regularly exercised to ensure proper operation [RCSA, 2009].

The inspection should also include the following:

• The appropriateness of the reservoir volume and detention times[EPA,2011]. If the amount of water stored is sufficiently more than the demand it may result in stagnant water and/or loss of chlorine residual. Possible accumu- lated sediment may absorb some/all available chlorine and promote bacterial growth.

• The filling/drainage regime of the reservoir (does reservoir run dry en risk re-disturbance of settled solids) [EPA, 2011].

• A water quality analysis: Test results should indicate total coliform bacte- ria, total and free chlorine residual, physical parameter and volatile organic chemicals [RCSA, 2009]. This analysis should be performed in accordance with relevant authorities.

• An inspection of the cathodic protection system, if applicable.

• Verification that the reservoir is at least 15 m from nearest sewage disposal system and 7 m from the nearest watercourse or storm water drain [RCSA,

2009].

• An assessment of the reservoir’s vulnerability to tampering, vandalism and other security issues [RCSA, 2009].

• An assessment of the required operation & maintenance activities needed to ensure continued level of service is maintained [RCSA, 2009].

• Confirmation that the reservoirs meet all necessary regulatory and statutory requirements [EPA, 2011].

Inspection frequency is dependent on the facility requirements and the available resources of the WSAs. Regulation only requires inspection once every 10 years, however it is recommended that atmospheric reservoirs be inspected every 3 - 5 years [[RCSA,2009].

Quarterly inspection of vents, screens, overflow screens, access hatches and drain liners is recommended [RCSA,2009].

Maintenance

Following the inspection, cleaning and disposal, it is the WSAs responsibility to ensure that the maintenance recommendations provided by the inspector are car- ried out [EPA, 2011].

Preventative maintenance is less expensive and is considered best practice. Pre- ventative maintenance ensures no significant change in the reservoir condition since the last inspection [EPA, 2011]. Unless stated otherwise, it is recommended that frequent flushing of the reservoir be performed. The flushing of the reservoir will remove any sediment build up as well as regulate the water detention time, which promotes hygiene [EPA, 2011]. Due to the less resource demanding nature of pre- ventative maintenance it is recommended that the WSAs incorporate preventative maintenance in the routine maintenance programme [EPA, 2011].

Preventative maintenance should begin with an inspection and should include the following [EPA,2011]:

• Site access and security inspection and repair. • Site maintenance inspection and repair.

• Foundation inspection and repair (where visible). • Grout, fibreboard inspection and repair.

• Manholes and access hatches inspection and replace. • Exterior overflow pipes.

• Vents. • Ladders.

Products used in the maintenance and repair works should be cleared by the WSAs and should be documented in a list of approved products [EPA,2011]. All activities performed on the reservoirs, should be recorded in a separate log and be stored electronically for future reference [EPA,2011].

Additional Maintenance Regime Elements

The following elements may also contribute to the management and maintenance of reservoirs within maintenance regimes. These elements include:

• Cleaning - This action includes isolating the reservoir from the network and washing the inside by means of a pressure wash to remove all contaminants that may negatively affect the water quality.

• Disinfection - Various disinfectants and procedures are used to ensure the reservoir is safe to store water in an hygienic manner.

• Disposal - This action includes the removal and disposal of the contaminants and disinfectant from the reservoir after cleaning and disinfection.

Adhere to Standards and Qualification

Before re-entering a reservoir into service it is required by law that it adheres to all the relevant health and safety standards. Inspectors may only enter the facility upon completion of the appropriate training. Appropriate training requirements are available from the Health and Safety Authority (HAS) [EPA, 2011].

All personnel, including maintenance staff and external contractors, should have been fully trained in the hygienic practices. Where necessary, training should be provided to include procedures required if a personnel member has an illness that may pose a contamination risk [EPA, 2011]. If a personnel member is multifunc- tional, works on water supply and sewage, extra care should be taken to avoid cross contamination. The UK provides hygienic water training through the hygienic training scheme, which upon completion certifies the participant with a ”National Water Hygiene Card” [EPA, 2011]. This certification represents the individual’s competency with regard to hygienic maintenance and operation practices.