The Arbor Hills Landfill has two permitted discharge points (outfalls) which impact Johnson Creek. Both of these permits are expiring and are in the process of being renewed (i.e. – basically new permits issued). The Conservancy Initiative recently submitted comments requesting EGLE add requirements for Arbor Hills to regularly monitor their discharges to Johnson Creek for regulated PFAS[1] chemical concentration. We believe the additional monitoring requirements are warranted due to the widespread PFAS contamination discovered at the site and the Arbor Hills Landfill’s poor environmental compliance record. Monthly monitoring for the regulated PFAS chemicals is a low-cost measure to protect the region’s only cold-water trout stream.
Below is a brief description of Arbor Hill’s permitted discharges to Johnson Creek.
Figure 1 - Location of Stormwater and NPDES Permit Discharges to Johnson Creek Tributary
Stormwater Discharge Permit
The Arbor Hills Landfill stormwater drainage area is estimated at approximately 365 acres which is 2.2% of the total Johnson Creek drainage area[2] and represents one of the largest (if not the largest) industrial or commercial impacts on Johnson Creek. Precipitation falling on the Arbor Hills Landfill site is collected in a Stormwater Detention Pond and discharged into an unnamed tributary of Johnson Creek. Historically, the Arbor Hills Landfill has been covered by a “General Stormwater Discharge Permit”. The General Permit does not require regular laboratory testing of the stormwater runoff. The General Permit only requires Arbor Hills to develop and certify they are following procedures to prevent the stormwater runoff from being impacted (Stormwater Pollution Prevention Plans) by the industrial operations at the site. To be fair, this is the process used for most manufacturing facilities.
Arbor Hills has obviously failed to properly implement effective plans to prevent stormwater runoff from being impacted by their operations. In March 2020, samples of the stormwater runoff collected in the stormwater detention pond contained 400 ppt PFOS (Michigan water standards limit PFOS at 12 ppt in surface waters). The noncompliant PFOS concentrations were not reported and were allowed to discharge to Johnson Creek and is continuing today. EGLE issued a violation notice and is currently negotiating a consent order to require the non-compliant discharge to be corrected and the site remediated.
The Conservancy Initiative submitted comments to EGLE on December 27, 2021[3] requesting the stormwater discharge permit covering the Arbor Hills Landfill be modified to include requirements to regularly sample and analyze the discharge for PFAS chemicals.
NPDES Permit for Gradient Control Pumps
The original landfill at the Arbor Hills site is referred to as Arbor Hills East. Arbor Hills East has been capped, is inactive, and is an unlined landfilled which predates many of the regulations which govern landfill operations today. A slurry wall was installed along the eastern boundary of Arbor Hills East to prevent leachates from migrating off-site and impacting adjacent properties and groundwater. A small amount of groundwater is pumped from near the slurry wall to induce a groundwater flow towards the slurry wall. This water is held in ponds, treated and discharged into an unnamed tributary of Johnson Creek under a National Pollution Discharge Elimination System permit (NPDES) issued by EGLE.
The current permit allows up to 100,000 gallons per day to be discharged from December 1 through April 30th. The current permit does not contain requirements to monitor for PFAS chemicals. The Conservancy Initiative submitted comments to EGLE on July 6, 2022[4] requesting the NPDES permit be modified to include requirements to regularly sample and analyze the discharge for PFAS chemicals.
[1] The PFAS acronym refers to a large family of chemicals, Per- and polyfluoroalkyl substances which are man-made chemicals that includes PFOA, PFOS, GenX, and many other chemicals. The predominant PFAS contamination found at Arbor Hills is PFOS or Perfluorooctane sulfonate, which is regulated in Michigan as a water contaminate.
[2] First Interim Short-Term Storm Water Characterization Study Report: PFAS (STSWCS), Arbor Hills Landfill, December 3, 2021 [Note – this is a massive file]
[3] [Comments on] Arbor Hills Landfill, Renewal of Certificate of Coverage MIS210766, General Permit MIS21000 – Industrial Stormwater CY2 General Permit, David Drinan, The Conservancy Initiative, December 27, 2021
[4] [Comments on] NPDES Permit MI0045713 Arbor Hills Landfill Remediation Site, David Drinan, The Conservancy Initiative, July 6, 2022