Where can dewatering water go: the sea, a storm drain or the sewer?

The aqueous media regulation defines dewatering as lowering groundwater to a safe level so that excavation can proceed below the natural groundwater level. The definition also covers water drawn from the surface soil when it appears during digging for development projects in coastal cities.^{1Aqueous reg. Art. 1}

The regulation tasks NCEC with proposing standards and controls for dewatering. The text itself contains no separate effluent table for dewatering water.^{2Aqueous reg. Art. 3(1)}

Discharging, draining or injecting untreated wastewater or any liquid into ground wells, any environmental medium or aquifer outcrops is prohibited for any reason.^{3Aqueous reg. Art. 5(1)}

The NCEC model conditions for a permit to establish require you to notify NCEC if dewatering water is present on site. Unless this is already covered in the study submitted to NCEC, you must take advice from an NCEC approved service provider on disposal and get approvals from the bodies that manage, transport and dispose of the water.^{4Permit guide, Appendix 1, item 5}

Discharging treated wastewater into environmental media is one of the activities that need an NCEC licence or permit. The application clause refers to discharging 'water', including into ground wells, and requires a technical study that shows:^{5Aqueous reg. Art. 8, First (1)(c) and Fourth (1)}

NCEC decides within 30 working days of a complete application and may extend this by 10 working days. It issues its decision only after the fees are collected.^{11Aqueous reg. Art. 8, First (2) and (3)}

The permit sets the discharge controls, requirements and standards, and is valid for no more than 6 months.^{12Aqueous reg. Art. 8, Fourth (3)}

The English and Arabic texts differ on the extension. The English reads 'another six (4) months', while the Arabic gives an extension of 4 further months. The regulation states that the Arabic version prevails.^{12Aqueous reg. Art. 8, Fourth (3)}

Before discharge, treated wastewater must meet Appendix 2 for coastal and marine waters or Appendix 3 for soil, land or surface water. The regulations reviewed do not mention storm drains by name, so the receiving medium is what links a discharge to one of these appendices.^{13Aqueous reg. Art. 6, First (1)}

The regulation does not state whether these appendices apply to groundwater from dewatering. The discharge permit itself sets the standards of discharge that apply to you.^{12Aqueous reg. Art. 8, Fourth (3)}

Selected limits follow. The value outside brackets is the average over the stated interval and the value in brackets is the maximum for any sample.^{14Aqueous reg. Appendix 2}

Monitoring programmes and the measurement and analysis of water before discharge must be done through a service provider approved by NCEC. Any activity holding a discharge permit must carry out the measurements NCEC requires.^{16Aqueous reg. Art. 6, Fourth (2) and (3)}

Monitoring and analysis data must be kept for at least 5 years and shown to NCEC on request.^{17Aqueous reg. Art. 6, Fourth (5)}

The treated sewage regulation prohibits draining storm water, groundwater or water from construction sites to the public system without a licence that sets the drainage method. The English text names the Ministry of Water and Electricity as the licensing body, so confirm the current licensing body before you apply.^{18TSE reg. Art. 5-3-5}

No liquid may be discharged to the public sewer if it exceeds the Table (1) limits. Water that does not meet them must be pre-treated first.^{19TSE reg. Art. 5-3-2 and 5-3-6}

Selected Table (1) limits for water entering the public sewer:^{20TSE reg. Table (1)}

Some materials may not enter the public sewer at all, including:^{21TSE reg. Art. 5-3-10}

The English translation of this regulation is provided for guidance. The Arabic text governs.^{26TSE reg. cover note}

The Regulation of Safety Procedures for Excavations applies to water and sanitation projects. It requires the contractor to dewater and keep the trench dry until construction is complete.^{27Excavation reg. Definitions and section 4 (Dewatering)}

Pumping may not start until the engineer supervising the dewatering scheme approves it. For wellpoint systems the contractor must provide hydraulic schemes showing pipe depths and pump capacities.^{28Excavation reg. section 4 (Dewatering)}

The regulation does not say where pumped water goes or what quality it must meet. The engineer's approval is a safety approval and is not an environmental discharge permit.^{28Excavation reg. section 4 (Dewatering)}

Not dewatering groundwater from a trench is a listed violation. The fine is 5,000 with a written notice the first time, rising to 15,000 and exclusion of the project manager the third time. The table does not name the currency.^{29Excavation reg. Penalties table, item 5}

NCEC can issue a permit to temporarily exceed the Appendix 2 and 3 standards. The application needs a technical study showing the exceedance will cause no severe and permanent harm, and it must include:^{30Aqueous reg. Art. 8, Third (1)}

This permit is valid for up to 6 months and can be extended by up to 4 months. The permittee must report periodically on progress with the action plan.^{35Aqueous reg. Art. 8, Third (3) and (4)}

These are the issues most likely to lead to fines or stoppages on a dewatering job:

Work through these points before the pumps are switched on: