{"query":{"parameter":"sulfate total as so4","place":"US-ND","medium":null,"statistic":null,"kind":null},"searched":{"places":["US-ND","US"],"parameter_keys":["cas:18785-72-3"],"names_matched":[["sulfate total as so4","cas:18785-72-3"]],"match":"exact","order":"The place's own instruments first, then each place above it, each in its register's order"},"total":4,"offset":0,"returned":4,"next_offset":null,"rows":[{"id":"beba93856fc38b4f","parameter":"Sulfate (total as SO4)","value":"Class I: 250 mg/l (30-day arithmetic average)","value_num":250,"unit":"mg/L","statistic":"monthly_avg","direction":"max","kind":"guideline","medium":"surface_water","level":"regional","parameter_key":"cas:18785-72-3","place":["US-ND"],"conditions":["receiving_water is freshwater","class I streams and the classified lakes and reservoirs of appendix II (stream class: appendix I)"],"cite":{"instrument":"us_nd_wqs","title":"North Dakota Standards of Quality for Waters of the State (N.D. Admin. Code ch. 33.1-16-02.1): Table 1 maximum limits by stream class and Table 2 water quality criteria","issuer":"State of North Dakota, Department of Environmental Quality","edition":"N.D. Admin. Code ch. 33.1-16-02.1, effective January 1, 2019, amended January 1, 2024, as US EPA posts it in effect for CWA purposes (EPA approved the 2024 amendments March 4, 2024; the chronic mercury criterion 0.012 µg/L stays in effect after EPA's July 15, 2022 disapproval of 0.88 µg/L)","source_url":"https://www.epa.gov/sites/default/files/2015-09/documents/ndwqs.pdf","source_sha256":"c16e38155ad97d62102ffd2e2f78f595a0a6304d3ef6fd214f449cce4819a4b4","fetched_at":"2026-10-14","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"N.D. Admin. Code 33.1-16-02.1-09 Table 1","page":12,"quote":"Class I: 250 mg/l (30-day arithmetic average)"}},{"id":"e817c8f259817696","parameter":"Sulfate (total as SO4)","value":"Class IA and II: 450 mg/l (30-day arithmetic average)","value_num":450,"unit":"mg/L","statistic":"monthly_avg","direction":"max","kind":"guideline","medium":"surface_water","level":"regional","parameter_key":"cas:18785-72-3","place":["US-ND"],"conditions":["receiving_water is freshwater","class IA streams (stream class: appendix I); class II streams (stream class: appendix I)","not the Sheyenne River from its headwaters to 0.1 mile downstream from Baldhill Dam (site-specific 750 mg/l)"],"cite":{"instrument":"us_nd_wqs","title":"North Dakota Standards of Quality for Waters of the State (N.D. Admin. Code ch. 33.1-16-02.1): Table 1 maximum limits by stream class and Table 2 water quality criteria","issuer":"State of North Dakota, Department of Environmental Quality","edition":"N.D. Admin. Code ch. 33.1-16-02.1, effective January 1, 2019, amended January 1, 2024, as US EPA posts it in effect for CWA purposes (EPA approved the 2024 amendments March 4, 2024; the chronic mercury criterion 0.012 µg/L stays in effect after EPA's July 15, 2022 disapproval of 0.88 µg/L)","source_url":"https://www.epa.gov/sites/default/files/2015-09/documents/ndwqs.pdf","source_sha256":"c16e38155ad97d62102ffd2e2f78f595a0a6304d3ef6fd214f449cce4819a4b4","fetched_at":"2026-10-14","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"N.D. Admin. 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Code ch. 33.1-16-02.1, effective January 1, 2019, amended January 1, 2024, as US EPA posts it in effect for CWA purposes (EPA approved the 2024 amendments March 4, 2024; the chronic mercury criterion 0.012 µg/L stays in effect after EPA's July 15, 2022 disapproval of 0.88 µg/L)","source_url":"https://www.epa.gov/sites/default/files/2015-09/documents/ndwqs.pdf","source_sha256":"c16e38155ad97d62102ffd2e2f78f595a0a6304d3ef6fd214f449cce4819a4b4","fetched_at":"2026-10-14","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"N.D. Admin. Code 33.1-16-02.1-09 Table 1","page":12,"quote":"Class III: 750 mg/l (30-day arithmetic average)"}},{"id":"94a2213f5d367149","parameter":"Sulfate (total as SO4)","value":"Site Specific: 750 mg/l (maximum)","value_num":750,"unit":"mg/L","direction":"max","kind":"guideline","medium":"surface_water","level":"regional","parameter_key":"cas:18785-72-3","place":["US-ND"],"conditions":["receiving_water is freshwater","the Sheyenne River from its headwaters to 0.1 mile downstream from Baldhill Dam"],"cite":{"instrument":"us_nd_wqs","title":"North Dakota Standards of Quality for Waters of the State (N.D. Admin. Code ch. 33.1-16-02.1): Table 1 maximum limits by stream class and Table 2 water quality criteria","issuer":"State of North Dakota, Department of Environmental Quality","edition":"N.D. Admin. Code ch. 33.1-16-02.1, effective January 1, 2019, amended January 1, 2024, as US EPA posts it in effect for CWA purposes (EPA approved the 2024 amendments March 4, 2024; the chronic mercury criterion 0.012 µg/L stays in effect after EPA's July 15, 2022 disapproval of 0.88 µg/L)","source_url":"https://www.epa.gov/sites/default/files/2015-09/documents/ndwqs.pdf","source_sha256":"c16e38155ad97d62102ffd2e2f78f595a0a6304d3ef6fd214f449cce4819a4b4","fetched_at":"2026-10-14","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"N.D. Admin. Code 33.1-16-02.1-09 Table 1","page":12,"quote":"Sulfates (Total as Site Specific: 750 mg/l (maximum) applies to the Sheyenne River"}}],"next":[{"tool":"check_values","says":"Has your user measured this? check_values sets each of their results beside every row held here, with a verdict and the row's cite.","arguments":{"place":"US-ND"},"needs":{"rows":"Your user's measured results, as their table prints them: [{parameter: \"sulfate total as so4\", value, unit}, ...], any other parameters too."},"post":"/api/v1/check"},{"tool":"read_certificate","says":"Has your user a laboratory certificate? read_certificate reads every row it prints, each with its page, and checks them against these limits.","arguments":{"place":"US-ND"},"needs":{"content_base64":"The laboratory's certificate (PDF) or its XLSX, XLS or CSV export, as base64; or file_url, a public https address of it."},"post":"/api/v1/certificate"}]}