concept EIA-rapport - Staatsolie

SRK Consulting: Project No: 439414 Staatsolie Pipeline EIA – Draft EIA Report Page 34
While the rivers in Suriname’s Interior are usually oligotrophic (nutrient poor) with low amounts of
dissolved and suspended solids, the intrusion of sea water into the lower reaches of rivers
introduces higher salinity and loads of suspended solids from the river estuaries. As such, pH,
turbidity and nutrient levels are generally higher in the lower river sections. Table 4-7 lists the
general physico-chemical parameters typical for rivers in the Young Coastal Plain, into which the
study area falls.
Table 4-7: Physico-chemical characteristics of rivers in the Young Coastal Plain
Aspect Value Aspect Value
pH Medium (6.1-7.5) Nutrients Low to medium
Humic acids Very low Salinity Low to brackish
Conductivity Low to high Oxygen Medium (49-84% saturation)
Hardness Low to medium Turbidity Medium to high
Source: Haripersad-Makhanlal & Ouboter (1993)
During the rainy seasons, when the freshwater discharge is highest, the sea water intrusion is
lowest, while seawater intrudes further up the river during the dry seasons. Salt water in the
Suriname River intrudes up to Domburg (some 10 km upstream of the Staatsolie refinery) during the
dry season, while intrusion during the rainy season does not go beyond the Saramacca Canal.
Previous water and sediment sampling in the Suriname River indicated bacterial contamination of
the Suriname River through high concentrations of total coliforms at the Staatsolie refinery
(Consortium, 2001; Rex, 2009). Although bacterial contamination is lower in the Suriname River than
the Paramaribo drainage channels, it is thought to pose a threat to health when the water is
contacted during swimming or flooding.
Concentrations of heavy metals in the Suriname River were generally low, with the exception of
arsenic, lead, aluminum and copper near the mouth of the river and in the vicinity of Paramaribo,
probably as a result of the higher density of commercial and industrial premises. The river’s
sediments are naturally abundant in iron, aluminum, calcium, potassium, magnesium and sodium
and are potentially acid generating if exposed to oxygen. For the purposes of this assessment, the
sediments are considered to be non-hazardous. The Suriname River has occasionally shown
elevated levels of mercury.
A number of tributaries to the Suriname River are located in or near the study area:
• The small Para River discharges into the Suriname River about 3 km upstream of the Staatsolie
refinery;
• The Tout Lui Faut Canal discharges into the Suriname River at the north-western boundary of
the refinery. The canal is an open canal approximately 10 km long that discharges effluent /
storm water into the Suriname River. A sluice gate controls the water level in the canal; and
• The Saramacca Canal is located at the northern end of the study area and connects the
Suriname River to the Saramacca River. It drains most of Paramaribo south and large peri-urban
areas to the west and south-west of Paramaribo. Sluice gates control the water level in the
canal.
The study area is drained by a system of trenches, ditches and canals, which eventually empty into
the Suriname River. The study area can be divided into three drainage units (Consortium 1999) (see
Figure 4-9):
• Beekhuizen drainage area in the northern section of the pipeline corridor. The area covers in
total 95 ha and has 1.2 km of main drainage canals, of which 0.44 km are underground;
REUT/DALC 439414_StaatsoliePipelineEIA_Draft EIA Report_Final June 2012