The Company records an allowance for doubtful accounts for receivable balances in an amount that is deemed by management to be sufficient to cover probable losses in accounts receivable, based on the analysis of the history of receipts and current guarantees and it does not expect to incur in additional significant losses. Inventories of supplies for consumption and maintenance of the water and sewage systems are stated at the lower of average cost of acquisition or realizable value, and are classified in current assets.