Australian PFAS Chemicals Map

Port Stanvac Refinery (closed 2003)

Site Contamination Audit Report: Former Adelaide (Port Stanvac) Wharf and Northern Beach Area. EPA South Australia 2021

p S20 “PFAS
Human health investigation levels PFAS concentrations in soil samples taken from the Wharf and NBA audit area compared against the adopted health based criteria are provided in attached Table T6 and are shown on attached Figure F14 (Wharf and Wharf Road area) and attached Figure F15 (northern NBA).

The assumed source area for PFAS compounds in soil (and groundwater) in the Wharf area is the former AFFF AST which was located east of the audit area (i.e. off-site, refer to attached Figure F3). The soil samples taken at the source area (off-site) indicate that PFOS was present in the crushed concrete of the pad at location SB10/003A_0.0-0.11 at a concentration of 1.57 mg/kg, which exceeds the adopted criterion for human health (1 mg/kg) for the audit site. The concentration of PFOS in concrete at this location also exceeded the adopted human health criterion for the sum of PFHxS and PFOS, which is also 1 mg/kg (refer to attached Figure F14). The concentration of PFOS in the soil sample from directly below the concrete
(SB10/003A_0.11-0.2) was 0.1 mg/kg, less than the adopted human health criteria (1 mg/kg) for the audit site. It cannot be stated whether this sample exceeded the sum of PFHxS and PFOS human health criteria as PFHxS was not analysed in soils during this investigation.

The concentrations of the PFOA in both the concrete and underlying soil (i.e. off-site) were less than the adopted health based criteria for the audit site (10 mg/kg).

The concrete pad was removed during the Wharf structure demolition between 2017 and 2018 and clean fillwas placed over the surface.

Three soil samples were collected from a single location (TP10/011, see attached Figure F14) within the Wharf portion of the audit area and analysed for PFAS compounds. This was located under the former pipe-rack along the Wharf alignment approximately 50 m west of the off-site AFFF source area. Detectable concentrations of PFOS were reported in the fill at 0.5 m (0.0032 mg/kg) and at 2 m (0.0037 mg/kg), however these were below the adopted health based criterion for the audit site (1 mg/kg).

Further soil sampling for PFAS was conducted along Wharf Road to assess PFAS concentrations in soils between the Wharf area and NBA (see attached Figure F14). Detectable PFOS concentrations were reported in all of the Wharf Road test pits, in both fill and natural material (maximum investigation depth was 0.7 m) varying from 0.0004 mg/kg to 0.102 mg/kg (HA17/01). These concentrations were all below the adopted health based criterion (1 mg/kg). The source of the reported PFAS in soils in the Wharf Road area is not clear, however it is likely related to impacted stormwater run-off down the cliff face (including small drainage lines) from the operational areas of the refinery area to the east. Three of the four locations (TP10/025, GS01 and TP10/28) are located near MW139 and MW140 which have PFAS impacts in groundwater. During the site visit on 4 April 2017, the auditor observed that runoff from the cliff was likely to
be occurring near the location of TP10/025/GS01. HA17/02 is located at the base of a small gully.

In the NBA portion of the audit area, the source of PFAS has been identified as being off-site (i.e. in the firetraining area and operational areas of the former refinery, located to the east of the NBA). Soil sampling in the NBA was conducted during the installation of the nested shallow and deep wells NBA- BH1, BH2, BH3 and BH4 (no soil samples could be taken from BH5) in 2016 and 2017. The concentrations of PFOS in the soil samples (taken in sand from depths varying from 0.2 to 2 m) ranged from <LOR (0.0002 mg/kg) to 0.05 mg/kg which are all below the adopted health based criterion (1 mg/kg). The results are shown in attached Figure F15.
Concentrations of PFOA in soils within the audit area were less than the adopted health based criterion (10 mg/kg) at all sample locations.

Ecological investigation levels

PFAS concentrations in soil samples taken from the Wharf and NBA audit area compared against the adopted ecological criteria are provided in attached Table T6 and are shown on attached Figure F14 (Wharf and Wharf Road area) and attached Figure F15 (northern NBA).

The reported concentrations of PFOS at TP10/011 in the wharf portion of the audit area are less than the adopted criteria for direct (1 mg/kg) and indirect (0.01 mg/kg) ecological exposure.

The concentrations of PFOS at five locations (7 individual samples) in the NBA area, including along Wharf Road (i.e. HA17/02, TP10/28, TP10/25, GS01 and NBA/BH1)4 exceeded the adopted criteria for indirect ecological exposure (0.01 mg/kg)5 (refer to attached Figure F14 and Figure F15). The exceedances ranged from 0.01 mg/kg to a maximum of 0.102 mg/kg (in HA17/01 at 0.2 m). The concentrations of PFOS in the other soil samples along Wharf Road in the NBA area were below the adopted ecological criteria.

The concentrations of PFOS in soil at NBA1 (located at the base of the erosional gully) exceeded the adopted ecological criterion for indirect ecological exposure (0.01 mg/kg), consistent with the runoff of stormwater (containing PFAS) from the refinery Plateau. The concentration of PFOS in the shallow sample (0.05 mg/kg at 0.5 m bgs) was higher than the sample from 2 m bgs (0.0178 mg/kg).

The reported concentrations of PFOS in the audit area did not exceed the adopted ecological criterion for direct ecological exposure criteria (1 mg/kg).

The reported concentrations of the sum of PFHxS and PFOS in the audit area did not exceed the adopted human health criteria (1 mg/kg)…

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PFAS Compounds

PFAS compounds were first analysed in wells in the Wharf and NBA area (GW140 only) in July 2015. The July 2015 sampling identified that the highest concentrations of PFAS compounds in groundwater were found in the Wharf area near the former AFFF infrastructure (GW013 and GW014). Selected groundwater wells in the Wharf area were subsequently sampled for PFAS compounds in November 2017 and October 2018.

The most recent analytical results (October 2018) for PFAS in groundwater at the Wharf area (including some off-site wells) are shown in attached Figure F21 and are provided in attached Table T12. Concentrations PFOS were reported in groundwater from 21 of the 23 wells sampled in October 2018. The two wells (i.e. MW318 and MW319) which reported PFOS < LOR (0.05 μg/l) are both located to the east of the audit area (i.e. off-site) and to the north east of the former AFFF AST. The highest concentrations of PFAS compounds in the Wharf portion of the audit area continue to be in groundwater from GW013 (PFOS 41 μg/l) and GW014 (PFOS 50 μg/l), which are close to the former AFFF tank that was located to the east of those wells. PFOS concentrations decrease to mostly less than 1 μg/l in monitoring wells away from GW013 and GW014. PFAS in groundwater is not delineated in any direction as detectable concentrations are identified in all wells sampled in the audit area.

Concentrations of PFOS in groundwater exceeded the adopted marine ecological criterion (0.00023 μg/l) in all wells sampled in the Wharf portion of the Audit area in October 2018. Concentrations of PFOS in the Wharf portion of the audit area which exceeded the criteria ranged from 0.005 μg/l (GW009) to 50 μg/l (GW014).

Concentrations of PFOS in groundwater exceeded the adopted recreational criterion (2 μg/l) in 5 wells sampled in the Wharf portion of the audit area in October 2018, ranging from 3.76 μg/l (MW325) to 50 μg/l (GW014).

Concentrations of PFHxS in groundwater exceeded the adopted recreational criterion (2 μg/l) in 4 wells sampled in the Wharf audit area in October 2018, ranging from 2.22 μg/l (MW325) to 17 μg/l (GW013).

Concentrations of the sum of PFHxS and PFOS in groundwater exceeded the adopted recreational criterion (2 μg/l) in 6 wells sampled in the Wharf audit area in October 2018, ranging from 2.5 μg/l (MW325) to 105 μg/l (GW014).

There is insufficient data to statistically assess trends in the concentrations of PFAS compounds in the Wharf portion of the audit area, however they have remained relatively consistent (i.e. within the same order of magnitude across the monitoring record.

PFAS compounds were identified in groundwater in the NBA area in July 2015 (PFOS of 7.6 μg/l in GW140). The presence of PFAS compounds in the NBA area in the absence of a local source resulted in the investigation of a potential source in the Plateau area and a pathway via the steeply incised erosional gully. To investigate the extent of PFAS in the groundwater and sediments at the base of the erosional gully, three nested (shallow and deep) wells were installed in an east – west transect from the base of the gully (NBA-BH1/1A) to the marine water interface (NBA- BH3/3A). Two nested wells were installed to the north (NBA – BH5/5A) and south (NBA – BH4/4A) of the main transect. Groundwater has been sampled from these wells on four occasions (October 2016, March 2017, July 2018 and August 2019). On two of these occasions (October 2016 and March 2017) the wells were sampled at high and low tide to assess the
impact of the tide on groundwater elevations and PFAS concentrations. Groundwater sampling at the NBA also included MW139, GW140 and MW140. The analytical results for PFAS in groundwater at the NBA are shown in attached Figure F22 and are provided in attached Table T12.

Concentrations of PFAS compounds were reported in groundwater from all wells in the NBA area (including MW139). The highest concentrations of PFAS compounds in groundwater at the NBA were in the wells forming the east – west transect at the base of the erosional gully (i.e. GW140, BH1/1A, BH2/2A and BH3/3A). The maximum reported concentration of PFOS in groundwater at the NBA was 42.3 μg/l in NBA/BH2 (October 2016). Of the nested well pairs, higher concentrations were observed in the deeper (i.e. 5.5 – 6 m bgs) wells compared to the shallow (2.5 m bgs), indicating some dilution / mixing with seawater in the shallow wells, and lower concentrations in the source water since the closure of the refinery. A lateral
(east to west) concentration gradient also exists between NBA1/1A and NBA3/3A where PFAS
concentrations decrease towards the marine interface. The concentrations of PFAS in the wells to the north (NBA5/5A) and south (NBA4/4A) of the transect (both shallow and deep) have been consistently 1 order of magnitude lower than the wells along the east -west transect at the mouth of the erosional gully. MW140 is located close to NBA4 reported similar PFAS concentrations to NBA4/4A.

The results of the most recent groundwater monitoring event (August 2019) in the NBA indicate the following:
• The concentrations of PFOS in groundwater at all locations in the NBA exceeded the adopted
marine ecosystem criterion (0.00023 μg/l) with concentrations ranging from 0.21 μg/l (NBA/BH3A) to 23 μg/l (NBA/BH2).
• The concentrations of PFOS in groundwater in six locations in the NBA exceeded the adopted
recreational criterion (2 μg/l) with concentrations ranging from 4.28 μg/l (NBA/BH2A) to 23 μg/l
(NBA/BH2).

• The concentrations of PFHxS in groundwater in six locations in the NBA exceeded the adopted
recreational criterion (2 μg/l) with concentrations ranging from 2.83 μg/l (GW140) to 13 μg/l
(NBA/BH1).
• The concentrations of the sum of PFHxS and PFOS in groundwater in seven locations in the NBA exceeded the adopted recreational criterion (2 μg/l) with concentrations ranging from 4.61 μg/l (MW140) to 35 μg/l (NBA/BH1).
• The concentrations of PFOA in groundwater in the NBA were less than the adopted marine
ecosystem criterion (19 μg/l) and the adopted recreational criterion (10 μg/l), with concentrations ranging from <LOR (0.01 μg/l) (NBA/BH3A) to 1.6 μg/l (NBA/BH2).

Groundwater summary

Residual concentrations of COPCs relating to the former Adelaide Refinery operations are present in groundwater at the audit site. Where they exceed the adopted criteria for this audit, they are generally isolated in areas associated with the former site activities / sources and are spatially delineated, or consistent with background groundwater concentrations at the audit site. Residual petroleum hydrocarbon concentrations in groundwater at the Wharf are stable and / or reducing and are less than the analytical LOR in wells closest to the Gulf St Vincent. The concentrations of PFAS in groundwater in both the Wharf and NBA portions of the audit area exceed the adopted criteria for the audit area. For the NBA, the PFOS concentrations were subject to a HHERA for both human and ecological receptors.

Other Waters

… • PFAS was also analysed in temporary monitoring wells (TMW01 – TMW11) located close to the discharge point of groundwater to the Gulf St Vincent. PFAS (limited suite) was analysed for in TMW01 – TMW11 in October 2015 and in an additional location (TMW12 – full suite) in November 2017.
• In October 2015, the concentrations of PFAS compounds (PFOS, PFOA, 6:2 FTS and FTS 8:2) in
water from TMWs 1 to 11 were less than their respective LORs (<0.05 μg/l, <0.05 μg/l, < 0.5 μg/l,
<0.5 μg/l).
• In November 2017, the concentration of PFOS (0.0035 μg/l) in water from TMW12 exceeded the marine aquatic ecosystem criteria (0.00023 μg/l).
• In November 2017, the concentration of PFOS (0.0035 μg/l), PFHxS (0.0018 μg/l) and the sum of PFOS and PFHxS (0.0053 μg/l) were less than the adopted health based criterion for recreational water (2 μg/l).

In addition to the groundwater well sampling in the NBA area, marine interface monitoring was conducted on two occasions (September 2017 and November 2017). This involved the excavation of eight shallow pits (MI/01 to MI/08) to 0.3 m in shallow weathered bedrock at the interface of the groundwater discharge into the marine environment and the collection of seepage water into these pits at low tide. The locations of these MIMs is provided in attached Figure F7 and the results are provided in attached Table T12.

The results of the MIM sampling indicate the following:
• Concentrations of PFOS were detected above LOR (0.01 μg/l) in water from all the MIM locations apart from MI/04 in September 2017 and MI/02 in November 2017.
• The reported concentrations of PFOS in water at all MIM locations exceeded the adopted marine ecosystem criterion (0.00023 μg/l) with concentrations ranging from 0.09 μg/l (MI/06) to 2.82 μg/l (MI/03).
• The concentration of PFOS in water from two of the MIM locations (2.16 μg/l at MI/03 in September 2017; and 2.82 μg/l at MI/03 in November 2017) exceeded the adopted health based criterion for recreational water (2 μg/l).
• The concentration of PFHxS in water from one of the MIM locations (2.14 μg/l at MI/05 in September 2017) exceeded the adopted health based criterion for recreational water (2 μg/l).
• The concentration of the sum of PFHxS and PFOS in water from four of the MIM locations, ranging from 2.07 μg/l (MI/08 in November 2017) to 3.86 μg/l (MI/03 in September 2017), exceeded the adopted health based criterion for recreational water (2 μg/l).
• The highest concentration of PFAS compounds are at MI/03 and are coincident with MI/03 being directly down gradient of the run-off areas identified in attached Figure F7.
In addition to the groundwater well and MIM sampling in the NBA area, Kleinfelder collected surface water runoff samples from locations SP01 – SP06 on three occasions (September 2017, August 208, August 2019), where surface water was available. The locations of these samples is shown in attached Figure F23 and the results are provided in attached Table T12. The results of the surface water runoff sampling indicate the following:
• The concentrations of PFOS in surface water from all the locations exceeded the adopted marine ecosystem criterion (0.00023 μg/l) on all three occasions (where water was present) with
concentrations ranging from 0.23 (SP03 in August 2019) to 45 μg/l (SP03 in August 2017).
• The concentrations of PFOS in surface water exceeded the adopted health based criterion for
recreational water (2 μg/l) on seven occasions (where water was present), ranging from 2.82 (SP05 in August 2019) to 45 μg/l (SP03 in August 2017).
• The concentrations of PFHxS in surface water from four of the surface water runoff locations
exceeded the adopted health based criterion for recreational water (2 μg/l) ranging from 2.48
(September 2017) to 21 μg/l (August 2017).

• The concentrations of PFHxS and PFOS in surface water from six of the surface water runoff
locations exceeded the adopted recreational criterion (2 μg/l) ranging from 3.16 μg/l (SP05 in August 2019) to 66 μg/l (SP03 in August 2017).
• The higher concentrations of PFAS compounds in surface water samples are at with SP03, which is located at the confluence of two run off areas (runoff area 1 and runoff area 2) as shown on attached Figure F23.

Other waters summary
Residual concentrations of PFAS are present in water discharging from shallow sediments to the marine environment at the Wharf (TMW12) and residual concentrations of PFAS are present in water discharging from shallow sediments to the marine environment at the NBA (marine interface sample locations). The water sampled appears to be predominantly seawater that recharged the beach sediments during the previous high tide (and is receding at low tide). The concentrations of metals in the Wharf TMWs exceeding the adopted criteria for this audit are generally consistent with background groundwater concentrations for the audit site, less than the analytical LOR or the adopted criteria in the most recent sampling event. PFAS
concentrations from shallow sediments to the marine environment across both the Wharf (TMW12) and the NBA exceed the adopted criteria for the site.

s33 Off-site impacts due to odour, air quality, stormwater and sedimentation

The auditor considers that there is no evidence of the migration of chemical substances from the site, and therefore off-site impacts, due to odour, air quality, stormwater or sedimentation.

As discussed above, the source of PFAS in the NBA is wastewater (historic) and stormwater runoff from the operational areas of the former refinery and down the erosional gully. While the sources of PFAS contaminated water and stormwater from the Plateau area to the erosional gully have been removed, some PFAS contaminated stormwater is expected to continue to discharge to the NBA from the erosional gully (and some smaller drainage lines along the cliff face). PFAS impacted runoff to the NBA is expected to decrease over time as there are no new sources of PFAS off-site.

The concentrations of PFAS in marine discharge / interface monitoring indicates that shallow water containing PFAS is discharging to the Gulf St Vincent at the Wharf area (TWM12) and NBA.
The potential for residual off-site contamination to migrate back onto the site

As discussed above, the source of soil and contamination in groundwater at the site is primarily the former refinery operations to the east of the audit site. As the primary sources of contamination have been removed and the site geology limits the movement of contaminated groundwater from east to west, the potential for contaminated soil and groundwater to migrate back onto the site is considered to be minimal.

As discussed above, the source of PFAS in the NBA is wastewater (historic) and stormwater runoff from the operational areas of the former refinery and down the erosional gully. While the sources of PFAS contaminated water and stormwater from the Plateau area to the erosional gully have been removed, PFAS contaminated stormwater is expected to continue to discharge to the NBA from the erosional gully (and some smaller drainage lines along the cliff face). The source of the PFAS in the stormwater is the residual PFAS concentrations in soil in the erosional gully. PFAS impacted runoff to the NBA is expected to decrease over time as there are no new sources of PFAS off-site.

Shallow water containing PFAS is discharging to the Gulf St Vincent at the Wharf area (TWM12) and NBA. There is the potential that PFAS (after being significantly diluted in the marine water) may migrate back onto the site during high tide (which will discharge on the following receding tide).

2017-20: Port Stanvac Refinery (closed 2003). PFAS Contaminated Site

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Port Stanvac Refinery (closed 2003)

Site Contamination Audit Report: Former Adelaide (Port Stanvac) Wharf and Northern Beach Area. EPA South Australia 2021

p S20 “PFAS
Human health investigation levels PFAS concentrations in soil samples taken from the Wharf and NBA audit area compared against the adopted health based criteria are provided in attached Table T6 and are shown on attached Figure F14 (Wharf and Wharf Road area) and attached Figure F15 (northern NBA).

The assumed source area for PFAS compounds in soil (and groundwater) in the Wharf area is the former AFFF AST which was located east of the audit area (i.e. off-site, refer to attached Figure F3). The soil samples taken at the source area (off-site) indicate that PFOS was present in the crushed concrete of the pad at location SB10/003A_0.0-0.11 at a concentration of 1.57 mg/kg, which exceeds the adopted criterion for human health (1 mg/kg) for the audit site. The concentration of PFOS in concrete at this location also exceeded the adopted human health criterion for the sum of PFHxS and PFOS, which is also 1 mg/kg (refer to attached Figure F14). The concentration of PFOS in the soil sample from directly below the concrete
(SB10/003A_0.11-0.2) was 0.1 mg/kg, less than the adopted human health criteria (1 mg/kg) for the audit site. It cannot be stated whether this sample exceeded the sum of PFHxS and PFOS human health criteria as PFHxS was not analysed in soils during this investigation.

The concentrations of the PFOA in both the concrete and underlying soil (i.e. off-site) were less than the adopted health based criteria for the audit site (10 mg/kg).

The concrete pad was removed during the Wharf structure demolition between 2017 and 2018 and clean fillwas placed over the surface.

Three soil samples were collected from a single location (TP10/011, see attached Figure F14) within the Wharf portion of the audit area and analysed for PFAS compounds. This was located under the former pipe-rack along the Wharf alignment approximately 50 m west of the off-site AFFF source area. Detectable concentrations of PFOS were reported in the fill at 0.5 m (0.0032 mg/kg) and at 2 m (0.0037 mg/kg), however these were below the adopted health based criterion for the audit site (1 mg/kg).

Further soil sampling for PFAS was conducted along Wharf Road to assess PFAS concentrations in soils between the Wharf area and NBA (see attached Figure F14). Detectable PFOS concentrations were reported in all of the Wharf Road test pits, in both fill and natural material (maximum investigation depth was 0.7 m) varying from 0.0004 mg/kg to 0.102 mg/kg (HA17/01). These concentrations were all below the adopted health based criterion (1 mg/kg). The source of the reported PFAS in soils in the Wharf Road area is not clear, however it is likely related to impacted stormwater run-off down the cliff face (including small drainage lines) from the operational areas of the refinery area to the east. Three of the four locations (TP10/025, GS01 and TP10/28) are located near MW139 and MW140 which have PFAS impacts in groundwater. During the site visit on 4 April 2017, the auditor observed that runoff from the cliff was likely to
be occurring near the location of TP10/025/GS01. HA17/02 is located at the base of a small gully.

In the NBA portion of the audit area, the source of PFAS has been identified as being off-site (i.e. in the firetraining area and operational areas of the former refinery, located to the east of the NBA). Soil sampling in the NBA was conducted during the installation of the nested shallow and deep wells NBA- BH1, BH2, BH3 and BH4 (no soil samples could be taken from BH5) in 2016 and 2017. The concentrations of PFOS in the soil samples (taken in sand from depths varying from 0.2 to 2 m) ranged from <LOR (0.0002 mg/kg) to 0.05 mg/kg which are all below the adopted health based criterion (1 mg/kg). The results are shown in attached Figure F15.
Concentrations of PFOA in soils within the audit area were less than the adopted health based criterion (10 mg/kg) at all sample locations.

Ecological investigation levels

PFAS concentrations in soil samples taken from the Wharf and NBA audit area compared against the adopted ecological criteria are provided in attached Table T6 and are shown on attached Figure F14 (Wharf and Wharf Road area) and attached Figure F15 (northern NBA).

The reported concentrations of PFOS at TP10/011 in the wharf portion of the audit area are less than the adopted criteria for direct (1 mg/kg) and indirect (0.01 mg/kg) ecological exposure.

The concentrations of PFOS at five locations (7 individual samples) in the NBA area, including along Wharf Road (i.e. HA17/02, TP10/28, TP10/25, GS01 and NBA/BH1)4 exceeded the adopted criteria for indirect ecological exposure (0.01 mg/kg)5 (refer to attached Figure F14 and Figure F15). The exceedances ranged from 0.01 mg/kg to a maximum of 0.102 mg/kg (in HA17/01 at 0.2 m). The concentrations of PFOS in the other soil samples along Wharf Road in the NBA area were below the adopted ecological criteria.

The concentrations of PFOS in soil at NBA1 (located at the base of the erosional gully) exceeded the adopted ecological criterion for indirect ecological exposure (0.01 mg/kg), consistent with the runoff of stormwater (containing PFAS) from the refinery Plateau. The concentration of PFOS in the shallow sample (0.05 mg/kg at 0.5 m bgs) was higher than the sample from 2 m bgs (0.0178 mg/kg).

The reported concentrations of PFOS in the audit area did not exceed the adopted ecological criterion for direct ecological exposure criteria (1 mg/kg).

The reported concentrations of the sum of PFHxS and PFOS in the audit area did not exceed the adopted human health criteria (1 mg/kg)…

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PFAS Compounds

PFAS compounds were first analysed in wells in the Wharf and NBA area (GW140 only) in July 2015. The July 2015 sampling identified that the highest concentrations of PFAS compounds in groundwater were found in the Wharf area near the former AFFF infrastructure (GW013 and GW014). Selected groundwater wells in the Wharf area were subsequently sampled for PFAS compounds in November 2017 and October 2018.

The most recent analytical results (October 2018) for PFAS in groundwater at the Wharf area (including some off-site wells) are shown in attached Figure F21 and are provided in attached Table T12. Concentrations PFOS were reported in groundwater from 21 of the 23 wells sampled in October 2018. The two wells (i.e. MW318 and MW319) which reported PFOS < LOR (0.05 μg/l) are both located to the east of the audit area (i.e. off-site) and to the north east of the former AFFF AST. The highest concentrations of PFAS compounds in the Wharf portion of the audit area continue to be in groundwater from GW013 (PFOS 41 μg/l) and GW014 (PFOS 50 μg/l), which are close to the former AFFF tank that was located to the east of those wells. PFOS concentrations decrease to mostly less than 1 μg/l in monitoring wells away from GW013 and GW014. PFAS in groundwater is not delineated in any direction as detectable concentrations are identified in all wells sampled in the audit area.

Concentrations of PFOS in groundwater exceeded the adopted marine ecological criterion (0.00023 μg/l) in all wells sampled in the Wharf portion of the Audit area in October 2018. Concentrations of PFOS in the Wharf portion of the audit area which exceeded the criteria ranged from 0.005 μg/l (GW009) to 50 μg/l (GW014).

Concentrations of PFOS in groundwater exceeded the adopted recreational criterion (2 μg/l) in 5 wells sampled in the Wharf portion of the audit area in October 2018, ranging from 3.76 μg/l (MW325) to 50 μg/l (GW014).

Concentrations of PFHxS in groundwater exceeded the adopted recreational criterion (2 μg/l) in 4 wells sampled in the Wharf audit area in October 2018, ranging from 2.22 μg/l (MW325) to 17 μg/l (GW013).

Concentrations of the sum of PFHxS and PFOS in groundwater exceeded the adopted recreational criterion (2 μg/l) in 6 wells sampled in the Wharf audit area in October 2018, ranging from 2.5 μg/l (MW325) to 105 μg/l (GW014).

There is insufficient data to statistically assess trends in the concentrations of PFAS compounds in the Wharf portion of the audit area, however they have remained relatively consistent (i.e. within the same order of magnitude across the monitoring record.

PFAS compounds were identified in groundwater in the NBA area in July 2015 (PFOS of 7.6 μg/l in GW140). The presence of PFAS compounds in the NBA area in the absence of a local source resulted in the investigation of a potential source in the Plateau area and a pathway via the steeply incised erosional gully. To investigate the extent of PFAS in the groundwater and sediments at the base of the erosional gully, three nested (shallow and deep) wells were installed in an east – west transect from the base of the gully (NBA-BH1/1A) to the marine water interface (NBA- BH3/3A). Two nested wells were installed to the north (NBA – BH5/5A) and south (NBA – BH4/4A) of the main transect. Groundwater has been sampled from these wells on four occasions (October 2016, March 2017, July 2018 and August 2019). On two of these occasions (October 2016 and March 2017) the wells were sampled at high and low tide to assess the
impact of the tide on groundwater elevations and PFAS concentrations. Groundwater sampling at the NBA also included MW139, GW140 and MW140. The analytical results for PFAS in groundwater at the NBA are shown in attached Figure F22 and are provided in attached Table T12.

Concentrations of PFAS compounds were reported in groundwater from all wells in the NBA area (including MW139). The highest concentrations of PFAS compounds in groundwater at the NBA were in the wells forming the east – west transect at the base of the erosional gully (i.e. GW140, BH1/1A, BH2/2A and BH3/3A). The maximum reported concentration of PFOS in groundwater at the NBA was 42.3 μg/l in NBA/BH2 (October 2016). Of the nested well pairs, higher concentrations were observed in the deeper (i.e. 5.5 – 6 m bgs) wells compared to the shallow (2.5 m bgs), indicating some dilution / mixing with seawater in the shallow wells, and lower concentrations in the source water since the closure of the refinery. A lateral
(east to west) concentration gradient also exists between NBA1/1A and NBA3/3A where PFAS
concentrations decrease towards the marine interface. The concentrations of PFAS in the wells to the north (NBA5/5A) and south (NBA4/4A) of the transect (both shallow and deep) have been consistently 1 order of magnitude lower than the wells along the east -west transect at the mouth of the erosional gully. MW140 is located close to NBA4 reported similar PFAS concentrations to NBA4/4A.

The results of the most recent groundwater monitoring event (August 2019) in the NBA indicate the following:
• The concentrations of PFOS in groundwater at all locations in the NBA exceeded the adopted
marine ecosystem criterion (0.00023 μg/l) with concentrations ranging from 0.21 μg/l (NBA/BH3A) to 23 μg/l (NBA/BH2).
• The concentrations of PFOS in groundwater in six locations in the NBA exceeded the adopted
recreational criterion (2 μg/l) with concentrations ranging from 4.28 μg/l (NBA/BH2A) to 23 μg/l
(NBA/BH2).

• The concentrations of PFHxS in groundwater in six locations in the NBA exceeded the adopted
recreational criterion (2 μg/l) with concentrations ranging from 2.83 μg/l (GW140) to 13 μg/l
(NBA/BH1).
• The concentrations of the sum of PFHxS and PFOS in groundwater in seven locations in the NBA exceeded the adopted recreational criterion (2 μg/l) with concentrations ranging from 4.61 μg/l (MW140) to 35 μg/l (NBA/BH1).
• The concentrations of PFOA in groundwater in the NBA were less than the adopted marine
ecosystem criterion (19 μg/l) and the adopted recreational criterion (10 μg/l), with concentrations ranging from <LOR (0.01 μg/l) (NBA/BH3A) to 1.6 μg/l (NBA/BH2).

Groundwater summary

Residual concentrations of COPCs relating to the former Adelaide Refinery operations are present in groundwater at the audit site. Where they exceed the adopted criteria for this audit, they are generally isolated in areas associated with the former site activities / sources and are spatially delineated, or consistent with background groundwater concentrations at the audit site. Residual petroleum hydrocarbon concentrations in groundwater at the Wharf are stable and / or reducing and are less than the analytical LOR in wells closest to the Gulf St Vincent. The concentrations of PFAS in groundwater in both the Wharf and NBA portions of the audit area exceed the adopted criteria for the audit area. For the NBA, the PFOS concentrations were subject to a HHERA for both human and ecological receptors.

Other Waters

… • PFAS was also analysed in temporary monitoring wells (TMW01 – TMW11) located close to the discharge point of groundwater to the Gulf St Vincent. PFAS (limited suite) was analysed for in TMW01 – TMW11 in October 2015 and in an additional location (TMW12 – full suite) in November 2017.
• In October 2015, the concentrations of PFAS compounds (PFOS, PFOA, 6:2 FTS and FTS 8:2) in
water from TMWs 1 to 11 were less than their respective LORs (<0.05 μg/l, <0.05 μg/l, < 0.5 μg/l,
<0.5 μg/l).
• In November 2017, the concentration of PFOS (0.0035 μg/l) in water from TMW12 exceeded the marine aquatic ecosystem criteria (0.00023 μg/l).
• In November 2017, the concentration of PFOS (0.0035 μg/l), PFHxS (0.0018 μg/l) and the sum of PFOS and PFHxS (0.0053 μg/l) were less than the adopted health based criterion for recreational water (2 μg/l).

In addition to the groundwater well sampling in the NBA area, marine interface monitoring was conducted on two occasions (September 2017 and November 2017). This involved the excavation of eight shallow pits (MI/01 to MI/08) to 0.3 m in shallow weathered bedrock at the interface of the groundwater discharge into the marine environment and the collection of seepage water into these pits at low tide. The locations of these MIMs is provided in attached Figure F7 and the results are provided in attached Table T12.

The results of the MIM sampling indicate the following:
• Concentrations of PFOS were detected above LOR (0.01 μg/l) in water from all the MIM locations apart from MI/04 in September 2017 and MI/02 in November 2017.
• The reported concentrations of PFOS in water at all MIM locations exceeded the adopted marine ecosystem criterion (0.00023 μg/l) with concentrations ranging from 0.09 μg/l (MI/06) to 2.82 μg/l (MI/03).
• The concentration of PFOS in water from two of the MIM locations (2.16 μg/l at MI/03 in September 2017; and 2.82 μg/l at MI/03 in November 2017) exceeded the adopted health based criterion for recreational water (2 μg/l).
• The concentration of PFHxS in water from one of the MIM locations (2.14 μg/l at MI/05 in September 2017) exceeded the adopted health based criterion for recreational water (2 μg/l).
• The concentration of the sum of PFHxS and PFOS in water from four of the MIM locations, ranging from 2.07 μg/l (MI/08 in November 2017) to 3.86 μg/l (MI/03 in September 2017), exceeded the adopted health based criterion for recreational water (2 μg/l).
• The highest concentration of PFAS compounds are at MI/03 and are coincident with MI/03 being directly down gradient of the run-off areas identified in attached Figure F7.
In addition to the groundwater well and MIM sampling in the NBA area, Kleinfelder collected surface water runoff samples from locations SP01 – SP06 on three occasions (September 2017, August 208, August 2019), where surface water was available. The locations of these samples is shown in attached Figure F23 and the results are provided in attached Table T12. The results of the surface water runoff sampling indicate the following:
• The concentrations of PFOS in surface water from all the locations exceeded the adopted marine ecosystem criterion (0.00023 μg/l) on all three occasions (where water was present) with
concentrations ranging from 0.23 (SP03 in August 2019) to 45 μg/l (SP03 in August 2017).
• The concentrations of PFOS in surface water exceeded the adopted health based criterion for
recreational water (2 μg/l) on seven occasions (where water was present), ranging from 2.82 (SP05 in August 2019) to 45 μg/l (SP03 in August 2017).
• The concentrations of PFHxS in surface water from four of the surface water runoff locations
exceeded the adopted health based criterion for recreational water (2 μg/l) ranging from 2.48
(September 2017) to 21 μg/l (August 2017).

• The concentrations of PFHxS and PFOS in surface water from six of the surface water runoff
locations exceeded the adopted recreational criterion (2 μg/l) ranging from 3.16 μg/l (SP05 in August 2019) to 66 μg/l (SP03 in August 2017).
• The higher concentrations of PFAS compounds in surface water samples are at with SP03, which is located at the confluence of two run off areas (runoff area 1 and runoff area 2) as shown on attached Figure F23.

Other waters summary
Residual concentrations of PFAS are present in water discharging from shallow sediments to the marine environment at the Wharf (TMW12) and residual concentrations of PFAS are present in water discharging from shallow sediments to the marine environment at the NBA (marine interface sample locations). The water sampled appears to be predominantly seawater that recharged the beach sediments during the previous high tide (and is receding at low tide). The concentrations of metals in the Wharf TMWs exceeding the adopted criteria for this audit are generally consistent with background groundwater concentrations for the audit site, less than the analytical LOR or the adopted criteria in the most recent sampling event. PFAS
concentrations from shallow sediments to the marine environment across both the Wharf (TMW12) and the NBA exceed the adopted criteria for the site.

s33 Off-site impacts due to odour, air quality, stormwater and sedimentation

The auditor considers that there is no evidence of the migration of chemical substances from the site, and therefore off-site impacts, due to odour, air quality, stormwater or sedimentation.

As discussed above, the source of PFAS in the NBA is wastewater (historic) and stormwater runoff from the operational areas of the former refinery and down the erosional gully. While the sources of PFAS contaminated water and stormwater from the Plateau area to the erosional gully have been removed, some PFAS contaminated stormwater is expected to continue to discharge to the NBA from the erosional gully (and some smaller drainage lines along the cliff face). PFAS impacted runoff to the NBA is expected to decrease over time as there are no new sources of PFAS off-site.

The concentrations of PFAS in marine discharge / interface monitoring indicates that shallow water containing PFAS is discharging to the Gulf St Vincent at the Wharf area (TWM12) and NBA.
The potential for residual off-site contamination to migrate back onto the site

As discussed above, the source of soil and contamination in groundwater at the site is primarily the former refinery operations to the east of the audit site. As the primary sources of contamination have been removed and the site geology limits the movement of contaminated groundwater from east to west, the potential for contaminated soil and groundwater to migrate back onto the site is considered to be minimal.

As discussed above, the source of PFAS in the NBA is wastewater (historic) and stormwater runoff from the operational areas of the former refinery and down the erosional gully. While the sources of PFAS contaminated water and stormwater from the Plateau area to the erosional gully have been removed, PFAS contaminated stormwater is expected to continue to discharge to the NBA from the erosional gully (and some smaller drainage lines along the cliff face). The source of the PFAS in the stormwater is the residual PFAS concentrations in soil in the erosional gully. PFAS impacted runoff to the NBA is expected to decrease over time as there are no new sources of PFAS off-site.

Shallow water containing PFAS is discharging to the Gulf St Vincent at the Wharf area (TWM12) and NBA. There is the potential that PFAS (after being significantly diluted in the marine water) may migrate back onto the site during high tide (which will discharge on the following receding tide).