A review of environmental governance and its effects on concentrate discharge from desalination plants in the Kingdom of Saudi Arabia

Abstract

The most likely environmental impact of concentrate discharges (in most instances twice the concentration of the ambient environment) leaking from desalination plants on local marine ecosystems has been controversially discussed for many years. Increasing water demand and lack of renewable natural water resources in Saudi Arabia also result in greater dependence on desalination and consequently amplify the impact on marine environment and multifactorial ecosystems in near-field areas of desalination discharges. Accurate scientific baseline data should furnish information on various factors such as intake- and outfall locality, brine (concentrate) discharge and chemical characteristics (i.e. effluent concentration, mass flow rates (flux)), local effects, and even cumulative effects of desalination activities, at least on a regional and even on a national scale. Even if such data were available, in many cases they are non-transparent and are not even accessible, or tend to be overlooked as a result of ambiguous desalination-related policies. This paper focuses on national environmental regulations in the Kingdom of Saudi Arabia (KSA) and how such regulations help control the flow of concentrate discharge into the receiving waters.

Keywords:

• Environmental impact assessment
• Seawater desalination
• Environmental regulations
• Concentrate discharge
• Marine ecosystems

Notes

Presented at the International Conference on Desalination for the Environment, Clean Water and Energy, European Desalination Society, 23–26 April 2012, Barcelona, Spain

¹International Desalination Association (2011).

²Enacted by Royal Decree No. M/34 dated 28/7/1422 Hejri (corresponding to 16 October 2001) and was published in the Official Gazette No 3868 dated 24/8/1422 Hejri (corresponding to 9 November 2001).

³Resolution No. 1/1/4/5/1/924 dated 03/08/1424 Hejri corresponding to 30 September 2003 (the “Implementing Regulations”) and published in the Official Gazette No. 3964 on 28/08/1424 Hejri (corresponding to 25 October 2003).

aPercentages (%) referred to in the table indicate the maximum allowable variations in comparison with local baseline conditions (unless otherwise stated, each interim guideline refers to a thirty [30-day average]).

bFacilities using, transferring, or storing oil and petroleum hydrocarbons are required to prepare, maintain, and update a spill prevention, control, and cleanup emergency response plan.

⁴Royal Commission Environmental Regulations (RCER-2010, Volume I, Regulations and Standards).

aWaters shall be free of all floating particles which may be attributed to wastewater or other discharges.

bTemperature differential with respect to the water temperature at cooling water canal intake.

cFor Yanbu only (refers to the maximum temperature at the edge of the mixing zone (approximately 600 m from the Port Barrier Reef)).

dNTU: nephalometric turbidity unit.

eNon-ionized concentration (pH and temperature dependent).

fInclusive range.

aTreated effluent discharge standards apply in Yanbu Industrial City to wastewater at the end of an outfall pipe and before discharge into the Red Sea.

bPermission to discharge variance streams is subject to Section 3.5.3. Standards are applicable to variance stream discharges before dilution with the main non-contact cooling water flow.

cApplicable to storm water discharges only, unless permission to discharge wastewater is granted under Section 3.4.10a.

dFor any parameters not identified, specific standards will be determined on a case-to-case basis.

eTemperature standard does not apply to variance stream discharges.

fDifferential temperature standard between seawater cooling intake and seawater cooling discharge.

gDifferential standard between seawater cooling intake and seawater cooling discharge for non-contact cooling water, absolute standard for all other discharges.

hChlorine residual is after 30 minutes contact and is total residual chlorine.

iDissolved oxygen requirement is a minimum concentration requirement.

jPAH: polycyclic aromatic hydrocarbons.

kAllowable range.

⁵Deep submerged discharges are generally preferred. Numerous design practices favor a steep discharge angle of 60° above horizontal. (However, examination of more recent laboratory data and the parametric application of CorJet, a jet integral model within the Cornell Mixing Zone Expert System, suggests that flatter discharge angles of about 30°–45° above horizontal may have considerable design advantages (preliminary) [16]. These relate to better dilution levels at the impingement location, especially if the bottom slope on port height is taken into account, better transport of mixing effluent during weak ambient current conditions, and the ability to locate in shallower waters).