Coolah Groundwater Investigation Drilling

Overview Warrumbungle Shire Council is inviting quotations from suitably qualified and experienced water bore drilling contractors to construct and test an investigative groundwater bore at the Coolah Town Wells site, located about 2.7 km northeast of Coolah, NSW. Scope The scope includes: Construction and testing of an investigative groundwater bore at the Coolah Town Wells site, targeting a confined sandstone interval at about 108-123 m below ground level Provision for a second test bore at Swanston Park, Coolah, targeting the Pilliga Sandstone from about 142 m to a nominal 200 m, should the Town Wells bore be abandoned Isolating and testing a single target aquifer and obtaining reliable, uncontaminated groundwater samples, with particular regard to iron, manganese and hardness Carrying out step-drawdown and 72-hour constant-rate pumping tests Capturing and disposing of all drilling fluids and produced water off site Discharging pump test water only to the locations nominated by Council The works are authorised under water supply work approval 90WA838736, which limits casing diameter at the point of water take to 150 mm. The works are staged around go/no-go decision points based on yield, water quality and test results. Objectives The pumping test results are intended to support a hydrogeological assessment of whether a future production bore could sustainably deliver 16 L/s. Information Requested Respondents must price two construction methods as part of their quotation: Option A: conventional mud rotary drilling Option B: mud rotary drilling above the target interval, followed by air drilling of the target interval below cemented intermediate casing Respondents should nominate their preferred method. Contractor Requirements Suitably qualified and experienced water bore drilling contractor Contract Terms and Conditions The contract will be based on AS 4000-1997, using a combination of lump sum and scheduled rate items Instructions to Tenderers Quotations will be assessed on a value-for-money basis in line with Council's Procurement Policy, including local benefit considerations. Full details, pricing schedules and supporting appendices, including previous test bore logs, geophysical logs and the approval, are provided in the RFQ documents. Site visits can be arranged on request.