Estate Service Asset - PDO

Petroleum Development Oman
Estate Services Asset
Environmental Assessment
2002 Review and Update
standards (Standard A-2) for land irrigation (refer Table 2.7 in Chapter 2). To control
the treatment processes and establish conformance to discharge standards, estate
services maintain a daily and weekly monitoring regime. The daily monitoring
program is carried out by plant operating staff (contractor staff) and the parameters
monitored daily are pH, chlorine, sludge volume index and dissolved oxygen. The
weekly monitoring is carried out by PDO’s Production Chemistry Laboratory staff in
MAF and includes total suspended solids, BOD, COD, ammoniacal nitrogen and
faecal coliforms.
The characteristics of the treated effluent from both the STPs as monitored during the
year 2002 are summarised below:
Table 4.1: Treated Sewage Characteristics
Parameter Units MAF-STP RAH-STP
Volume of sewage m 3 /d ~500
(Estimated)
~500
(Estimated)
pH None 7.8-8.4
(XN=0/41)
7.6-8.3
(XN=0/41)
Total suspended solids mg/L 0.4-13.2
(XN=0/41)
1-7.2
(XN=0/41)
Ammoniacal nitrogen mg/L 0.1->10
(XN=13/41)
0.1->10
(XN=1/41)
Biological oxygen demand mg/L 7-17
(XN=0/41)
7-13
(XN=0/41)
Chemical oxygen demand mg/L 10-170
(XN=0/41)
12-83
(XN=0/41)
Free chlorine mg/L 0-5
(XN=33/41)
0-5
(XN=24/41)
Notes: XN = Number times regulatory standards exceeded per total number of times monitored. As per the STP
operating manual, free chlorine in the treated effluent shall be maintained within 0.5-1.5 mg/L.
From the above values in table 4.1, it is observed that the number of exceedance per
total number of times monitored is high for ammoniacal nitrogen and free chlorine.
On the other hand, some critical parameters are not monitored such as heavy metals,
phenols, sodium absorption ratios, etc. The recommendations and additional
mitigation measures are presented in chapter 7 of this report.
4.4 Solid Wastes
4.4.1 Sources of Generation
In PDO, the solid wastes are classified into broad categories as non-hazardous and
hazardous. The sub-groups in each category are as below:
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