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INFORMATION SHEET SIMPSON INVESTMENT COMPANY SIMPSON PAPER COMPANY RIPON MILL SAN JOAQUIN COUNTY The Simpson Paper Company (owned by Simpson Investment Company, Seattle, Washington) operates a paper mill within the city limits of Ripon, San Joaquin County. The Ripon Mill manufactures several grades of fine papers from purchased pulp. The mill's maximum daily production rate is 280,000 lbs (127,272 kgs) of paper. Waste Discharge Requirements Order No. 77-286, NPDES No. CA0004006, adopted by the Board on 16 December 1977, prescribes requirements for the discharge of industrial wastewater and stormwater runoff from primary and secondary treatment facilities at the mill. Order No. 77-286 (NPDES CA0004006) was rescinded by Waste Discharge Requirements Order No. 83-001, NPDES CA0004006, adopted by the Board on 28 January 1983. Order No. 83-001 expired on 1 February 1988. The Ripon Mill proposes to intermittently discharge a maximum 1.5 mgd of industrial wastewater from secondary treatment facilities to land. In addition, the mill will discharge a maximum 1.8 mgd (6,817,000 liters/day) of combined industrial wastewater and stormwater runoff from primary and secondary treatments to 90 acres (36.5 ha). The mill facility occupies 228 acres. Prior to July 1975, the Ripon Mill discharged to the Stanislaus River continuously or intermittently. Since July 1975, the mill has been able to contain all wastewater on land. The Ripon Mill no longer discharges wastewater into the Stanislaus River. The discharge of wastewater to the Stanislaus River or any other surface water or drainage course is prohibited. The Ripon Mill has applied for the waste discharge requirements, covering a discharge of waste to land in place of their discharge to surface waters. The Ripon Mill has proposed several changes to reduce the amount of salts in their discharge. These changes include using a distillation process to concentrate water softener regeneration waste in order to make it acceptable as brine for commercial use off-site; altering the process chemistry to reduce alum consumption, and installing new water supply wells screened in an aquifer which have less dissolved salts. These changes should reduce the amount of salts in the final effluent to the percolation ponds, such that the level of salts in the discharge will not degrade water quality beneath the site. Ripon Mill's consultant, David A. Lawrence, C.E.G. 618, has certified that Ripon Mill discharge is not a 'designated waste'. The Ripon Mill will conduct pond and ground water monitoring to confirm that the discharge is not impacting ground water. Additionally, Ripon Mill will be required to conduct a ground water study every five years to determine the effectiveness of the operational and wastewater management changes on reducing the amount of salts in the discharge and the overall impact to the aquifers below the site. RAE:lsb:6/30/93