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HomeMy WebLinkAboutNCS000304_Outfall Narrative_20180917OUTFALL NARRATIVE OUTFALLS — Our 2009 permit lists 4 outfalls, with the removal of the parking lot outfall we will have 3 outfalls: • OUTFALL 1 (aka SOUTHEAST OUTFALL): As noted in your email this outfall collects rainwater strictly from non -industrial activities (i.e. parking lot and landscaped areas). We therefore agree that it should not be covered under the NPDES permit. Our attached new topographical map now notes that this area is 'Non Industrial Activity'. • OUTFALL 2 (aka SOUTH OUTFALL): As indicated in your email there was a project years ago to help us capture more Stormwater for recycling purposes. This project installed a pump system at the OUTFALL 2 area which can handle a 2 year storm event. The water from this outfall is therefore collected and pumped over to the South Stormwater Collection Pond. Since the collection/pumping system is only built to withstand a 2 year event, we agree that it should still be captured in the NPDES permit. • OUTFALL 3 (aka NORTH OUTFALL): The North Outfall is set back in the woods as indicated on the attached map. This outfall discharges into a creek that runs through our property. In the past, we have not been able to gather samples from this outfall. Due to the lay of the land, the outfall only discharges during extreme weather events. Last year, we spoke with Bethany Georgoulias in regards to sampling this outfall. She informed us that the state does not require us to go out into extreme weather events to gather samples. She said it would be sufficient to use the West Outfall samples as representative data for this outfall (as well as for Outfall 2 in the event that we had a greater than 2 year storm event and it discharged). We discussed this with you as well and you also referred to a 'representative' status for this outfall. We understand that the permit will not list the outfall as a 'representative' status, but that we can note the representative status on our DMRs. • OUTFALL 4 (aka WEST OUTFALL): The West Outfall is located back in the woods. It is made up of a culmination of overflow from the South Stormwater Collection Pond as well as runoff from the top of the landfill. This runoff and overflow goes through a culvert where it is treated with CO2, if needed, and then flows into the woods. In the event that the West Stormwater Collection Pond's pumping system were to malfunction, or in the event of extreme weather, the West Stormwater Collection Pond may overflow. This overflow will be captured by Outfall 4. We sample this outfall at the edge of our property where it is most accessible. STORMWATER COLLECTION PONDS — Our site captures Stormwater through the use of 3 stormwater collection ponds. These are separate and not to be confused with our outfalls. These ponds are strictly for capturing and holding STORMWATER (except for the west pond which also collects slag cooling water runoff), they do not hold process water of any kind. In the event of a severe weather event, the ponds may overflow. Overflow water will flow to one of our 3 OUTFALLS. SOUTH STORMWATER COLLECTION POND: The South Stormwater Collection collects rainfall runoff from storm drains throughout the majority of the mill as well as water from the West Stormwater Collection Pond. Water from this collection pond is pumped to the North Stormwater Collection Pond. In the event that this South Stormwater Collection Pond overflows, excess water will pass under a culvert in the road, flow down the drainage area around the landfill, be treated with CO2 as needed and then make its way back to OUTFALL 4. • WEST STORMWATER COLLECTION POND: The West Stormwater Collection Pond consists of rainfall runoff as well as runoff from slag cooling operations. Water from this pond is treated with CO2 before it is pumped to the South Stormwater Collection Pond. • NORTH STORMWATER COLLECTION POND: The North Stormwater Collection Pond consists of water from storm drains as well as water pumped from the South Stormwater Collection Pond. The North Stormwater Collection Pond is used as makeup water for our caster process water pond.