{"query":{"parameter":"benzidine","place":"US-TX","medium":null,"statistic":null,"kind":null},"searched":{"places":["US-TX","US"],"parameter_keys":["cas:92-87-5","cas:91-94-1","cas:119-90-4","cas:119-93-7"],"names_matched":[["benzidine","cas:92-87-5"],["dichloro 3 3 benzidine","cas:91-94-1"],["1 1 biphenyl 4 4 diamine 3 3 dichloro","cas:91-94-1","1 1 biphenyl 4 4 diamine"],["1 1 biphenyl 4 4 diamine 3 3 dimethoxy","cas:119-90-4","1 1 biphenyl 4 4 diamine"],["1 1 biphenyl 4 4 diamine 3 3 dimethyl","cas:119-93-7","1 1 biphenyl 4 4 diamine"]],"match":"exact+contains","order":"The place's own instruments first, then each place above it, each in its register's order; rows for a marine receiving water after the rest, as none of the place's own rows names a marine, salt, estuarine, coastal or ocean water","not_sent":{"rows":65,"names":["Dimethoxybenzidine, 3,3'-","Dimethylbenzidine, 3,3'-","Dichlorobenzidine, 3,3-","3,3'-Dichlorobenzidine","Dichlorobenzidine, 3,3'-"],"says":"65 rows share a parameter key with a longer name holding \"benzidine\" but are printed under names without these words (that key is wider than the name), or keyed to a CAS number \"benzidine\" does not name (another substance, whatever words its name holds): not sent. Ask for one by its name or CAS number."}},"total":37,"offset":0,"returned":37,"next_offset":null,"rows":[{"id":"b670cd4fa077a197","parameter":"Benzidine","value":"1.5E-02","value_num":0.015,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 1, Residential Soil, TotSoilComb, 0.5 acre source area","page":10,"quote":"Benzidine 92-87-5 1.5E-02 I c I 1.1E-05 I c I 1.1E-03 I c I 6.3E-02 I c I 1.4E+01 I c I ─ 1.3E-02 I c I 5.5E-06 I c I 5.5E-04 I c I 3.2E-02 I c I 1.2E+00 I c I ─"}},{"id":"4a2300c9991428c9","parameter":"Benzidine","value":"1.1E-05","value_num":0.000011,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 1, Residential Soil, GWSoilIng, 0.5 acre source area","page":10,"quote":"Benzidine 92-87-5 1.5E-02 I c I 1.1E-05 I c I 1.1E-03 I c I 6.3E-02 I c I 1.4E+01 I c I ─ 1.3E-02 I c I 5.5E-06 I c I 5.5E-04 I c I 3.2E-02 I c I 1.2E+00 I c I ─"}},{"id":"227c7d884c773a30","parameter":"Benzidine","value":"1.1E-03","value_num":0.0011,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 1, Residential Soil, GWSoilClass 3, 0.5 acre source area","page":10,"quote":"Benzidine 92-87-5 1.5E-02 I c I 1.1E-05 I c I 1.1E-03 I c I 6.3E-02 I c I 1.4E+01 I c I ─ 1.3E-02 I c I 5.5E-06 I c I 5.5E-04 I c I 3.2E-02 I c I 1.2E+00 I c I ─"}},{"id":"8848fb4d3b0eede1","parameter":"Benzidine","value":"6.3E-02","value_num":0.063,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 1, Residential Soil, AirSoilInh-V, 0.5 acre source area","page":10,"quote":"Benzidine 92-87-5 1.5E-02 I c I 1.1E-05 I c I 1.1E-03 I c I 6.3E-02 I c I 1.4E+01 I c I ─ 1.3E-02 I c I 5.5E-06 I c I 5.5E-04 I c I 3.2E-02 I c I 1.2E+00 I c I ─"}},{"id":"dbb8de9a1c3fc3c2","parameter":"Benzidine","value":"1.4E+01","value_num":14,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 1, Residential Soil, AirGW-SoilInh-V, 0.5 acre source area","page":10,"quote":"Benzidine 92-87-5 1.5E-02 I c I 1.1E-05 I c I 1.1E-03 I c I 6.3E-02 I c I 1.4E+01 I c I ─ 1.3E-02 I c I 5.5E-06 I c I 5.5E-04 I c I 3.2E-02 I c I 1.2E+00 I c I ─"}},{"id":"1a56500992ca7dc3","parameter":"Benzidine","value":"1.3E-02","value_num":0.013,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 1, Residential Soil, TotSoilComb, 30 acre source area","page":10,"quote":"Benzidine 92-87-5 1.5E-02 I c I 1.1E-05 I c I 1.1E-03 I c I 6.3E-02 I c I 1.4E+01 I c I ─ 1.3E-02 I c I 5.5E-06 I c I 5.5E-04 I c I 3.2E-02 I c I 1.2E+00 I c I ─"}},{"id":"77aff3f6124f4947","parameter":"Benzidine","value":"5.5E-06","value_num":0.0000055,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 1, Residential Soil, GWSoilIng, 30 acre source area","page":10,"quote":"Benzidine 92-87-5 1.5E-02 I c I 1.1E-05 I c I 1.1E-03 I c I 6.3E-02 I c I 1.4E+01 I c I ─ 1.3E-02 I c I 5.5E-06 I c I 5.5E-04 I c I 3.2E-02 I c I 1.2E+00 I c I ─"}},{"id":"73311a077c21730b","parameter":"Benzidine","value":"5.5E-04","value_num":0.00055,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 1, Residential Soil, GWSoilClass 3, 30 acre source area","page":10,"quote":"Benzidine 92-87-5 1.5E-02 I c I 1.1E-05 I c I 1.1E-03 I c I 6.3E-02 I c I 1.4E+01 I c I ─ 1.3E-02 I c I 5.5E-06 I c I 5.5E-04 I c I 3.2E-02 I c I 1.2E+00 I c I ─"}},{"id":"da962987879e23a0","parameter":"Benzidine","value":"3.2E-02","value_num":0.032,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 1, Residential Soil, AirSoilInh-V, 30 acre source area","page":10,"quote":"Benzidine 92-87-5 1.5E-02 I c I 1.1E-05 I c I 1.1E-03 I c I 6.3E-02 I c I 1.4E+01 I c I ─ 1.3E-02 I c I 5.5E-06 I c I 5.5E-04 I c I 3.2E-02 I c I 1.2E+00 I c I ─"}},{"id":"cfb1e371211a1ff2","parameter":"Benzidine","value":"1.2E+00","value_num":1.2,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 1, Residential Soil, AirGW-SoilInh-V, 30 acre source area","page":10,"quote":"Benzidine 92-87-5 1.5E-02 I c I 1.1E-05 I c I 1.1E-03 I c I 6.3E-02 I c I 1.4E+01 I c I ─ 1.3E-02 I c I 5.5E-06 I c I 5.5E-04 I c I 3.2E-02 I c I 1.2E+00 I c I ─"}},{"id":"611a7496ce7c45ff","parameter":"Benzidine","value":"4.7E-02","value_num":0.047,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 2, Commercial/Industrial Soil, TotSoilComb, 0.5 acre source area","page":25,"quote":"Benzidine 92-87-5 4.7E-02 c 2.4E-05 I c 2.4E-03 I c 1.1E-01 I c 2.3E+01 I c ─ 3.3E-02 c 1.2E-05 I c 1.2E-03 I c 5.4E-02 I c 1.9E+00 I c ─"}},{"id":"2961554e592a3ef3","parameter":"Benzidine","value":"2.4E-05","value_num":0.000024,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 2, Commercial/Industrial Soil, GWSoilIng, 0.5 acre source area","page":25,"quote":"Benzidine 92-87-5 4.7E-02 c 2.4E-05 I c 2.4E-03 I c 1.1E-01 I c 2.3E+01 I c ─ 3.3E-02 c 1.2E-05 I c 1.2E-03 I c 5.4E-02 I c 1.9E+00 I c ─"}},{"id":"462f5175636ea71b","parameter":"Benzidine","value":"2.4E-03","value_num":0.0024,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 2, Commercial/Industrial Soil, GWSoilClass 3, 0.5 acre source area","page":25,"quote":"Benzidine 92-87-5 4.7E-02 c 2.4E-05 I c 2.4E-03 I c 1.1E-01 I c 2.3E+01 I c ─ 3.3E-02 c 1.2E-05 I c 1.2E-03 I c 5.4E-02 I c 1.9E+00 I c ─"}},{"id":"1082f4104993b052","parameter":"Benzidine","value":"1.1E-01","value_num":0.11,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 2, Commercial/Industrial Soil, AirSoilInh-V, 0.5 acre source area","page":25,"quote":"Benzidine 92-87-5 4.7E-02 c 2.4E-05 I c 2.4E-03 I c 1.1E-01 I c 2.3E+01 I c ─ 3.3E-02 c 1.2E-05 I c 1.2E-03 I c 5.4E-02 I c 1.9E+00 I c ─"}},{"id":"41e36b235be4fd6a","parameter":"Benzidine","value":"2.3E+01","value_num":23,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 2, Commercial/Industrial Soil, AirGW-SoilInh-V, 0.5 acre source area","page":25,"quote":"Benzidine 92-87-5 4.7E-02 c 2.4E-05 I c 2.4E-03 I c 1.1E-01 I c 2.3E+01 I c ─ 3.3E-02 c 1.2E-05 I c 1.2E-03 I c 5.4E-02 I c 1.9E+00 I c ─"}},{"id":"c0463608ce025db6","parameter":"Benzidine","value":"3.3E-02","value_num":0.033,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 2, Commercial/Industrial Soil, TotSoilComb, 30 acre source area","page":25,"quote":"Benzidine 92-87-5 4.7E-02 c 2.4E-05 I c 2.4E-03 I c 1.1E-01 I c 2.3E+01 I c ─ 3.3E-02 c 1.2E-05 I c 1.2E-03 I c 5.4E-02 I c 1.9E+00 I c ─"}},{"id":"05b0b9a091d77651","parameter":"Benzidine","value":"1.2E-05","value_num":0.000012,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 2, Commercial/Industrial Soil, GWSoilIng, 30 acre source area","page":25,"quote":"Benzidine 92-87-5 4.7E-02 c 2.4E-05 I c 2.4E-03 I c 1.1E-01 I c 2.3E+01 I c ─ 3.3E-02 c 1.2E-05 I c 1.2E-03 I c 5.4E-02 I c 1.9E+00 I c ─"}},{"id":"7992d40b39690e31","parameter":"Benzidine","value":"1.2E-03","value_num":0.0012,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 2, Commercial/Industrial Soil, GWSoilClass 3, 30 acre source area","page":25,"quote":"Benzidine 92-87-5 4.7E-02 c 2.4E-05 I c 2.4E-03 I c 1.1E-01 I c 2.3E+01 I c ─ 3.3E-02 c 1.2E-05 I c 1.2E-03 I c 5.4E-02 I c 1.9E+00 I c ─"}},{"id":"6eab87af22b51fba","parameter":"Benzidine","value":"5.4E-02","value_num":0.054,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 2, Commercial/Industrial Soil, AirSoilInh-V, 30 acre source area","page":25,"quote":"Benzidine 92-87-5 4.7E-02 c 2.4E-05 I c 2.4E-03 I c 1.1E-01 I c 2.3E+01 I c ─ 3.3E-02 c 1.2E-05 I c 1.2E-03 I c 5.4E-02 I c 1.9E+00 I c ─"}},{"id":"1f3c761b65d77dea","parameter":"Benzidine","value":"1.9E+00","value_num":1.9,"unit":"mg/kg","direction":"max","kind":"threshold","medium":"soil","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 2, Commercial/Industrial Soil, AirGW-SoilInh-V, 30 acre source area","page":25,"quote":"Benzidine 92-87-5 4.7E-02 c 2.4E-05 I c 2.4E-03 I c 1.1E-01 I c 2.3E+01 I c ─ 3.3E-02 c 1.2E-05 I c 1.2E-03 I c 5.4E-02 I c 1.9E+00 I c ─"}},{"id":"c4900a8ee589974a","parameter":"Benzidine","value":"4.0E-06","value_num":0.000004,"unit":"mg/L","direction":"max","kind":"threshold","medium":"groundwater","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 3, Groundwater, GWGWIng, Residential","page":39,"quote":"Benzidine 92-87-5 4.0E-06 I c 4.0E-04 I c 5.0E+00 I c 8.4E-01 c 8.9E-06 I c 8.9E-04 I c 8.4E+00 I c 1.4E+00 c ─"}},{"id":"16bb0f5f886595c1","parameter":"Benzidine","value":"4.0E-04","value_num":0.0004,"unit":"mg/L","direction":"max","kind":"threshold","medium":"groundwater","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 3, Groundwater, GWGWClass3, Residential","page":39,"quote":"Benzidine 92-87-5 4.0E-06 I c 4.0E-04 I c 5.0E+00 I c 8.4E-01 c 8.9E-06 I c 8.9E-04 I c 8.4E+00 I c 1.4E+00 c ─"}},{"id":"60d5f1dcb1080920","parameter":"Benzidine","value":"5.0E+00","value_num":5,"unit":"mg/L","direction":"max","kind":"threshold","medium":"groundwater","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 3, Groundwater, AirGWInh-V 0.5 acre source area, Residential","page":39,"quote":"Benzidine 92-87-5 4.0E-06 I c 4.0E-04 I c 5.0E+00 I c 8.4E-01 c 8.9E-06 I c 8.9E-04 I c 8.4E+00 I c 1.4E+00 c ─"}},{"id":"b6ec31b680fa7e28","parameter":"Benzidine","value":"8.4E-01","value_num":0.84,"unit":"mg/L","direction":"max","kind":"threshold","medium":"groundwater","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","residential land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 3, Groundwater, AirGWInh-V 30 acre source area, Residential","page":39,"quote":"Benzidine 92-87-5 4.0E-06 I c 4.0E-04 I c 5.0E+00 I c 8.4E-01 c 8.9E-06 I c 8.9E-04 I c 8.4E+00 I c 1.4E+00 c ─"}},{"id":"28b06ef83bd43baf","parameter":"Benzidine","value":"8.9E-06","value_num":0.0000089,"unit":"mg/L","direction":"max","kind":"threshold","medium":"groundwater","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 3, Groundwater, GWGWIng, Commercial/Industrial","page":39,"quote":"Benzidine 92-87-5 4.0E-06 I c 4.0E-04 I c 5.0E+00 I c 8.4E-01 c 8.9E-06 I c 8.9E-04 I c 8.4E+00 I c 1.4E+00 c ─"}},{"id":"2cb57f2419101e81","parameter":"Benzidine","value":"8.9E-04","value_num":0.00089,"unit":"mg/L","direction":"max","kind":"threshold","medium":"groundwater","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 3, Groundwater, GWGWClass3, Commercial/Industrial","page":39,"quote":"Benzidine 92-87-5 4.0E-06 I c 4.0E-04 I c 5.0E+00 I c 8.4E-01 c 8.9E-06 I c 8.9E-04 I c 8.4E+00 I c 1.4E+00 c ─"}},{"id":"078305d0ac1dce99","parameter":"Benzidine","value":"8.4E+00","value_num":8.4,"unit":"mg/L","direction":"max","kind":"threshold","medium":"groundwater","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 0.5 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 3, Groundwater, AirGWInh-V 0.5 acre source area, Commercial/Industrial","page":39,"quote":"Benzidine 92-87-5 4.0E-06 I c 4.0E-04 I c 5.0E+00 I c 8.4E-01 c 8.9E-06 I c 8.9E-04 I c 8.4E+00 I c 1.4E+00 c ─"}},{"id":"9beb666cf94227d3","parameter":"Benzidine","value":"1.4E+00","value_num":1.4,"unit":"mg/L","direction":"max","kind":"threshold","medium":"groundwater","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["1 In accordance with §350.72(b), when establishing Tier 1 PCLs for individual COCs for each of the individual and combined human health exposure pathways, the person must evaluate whether the PCLs need to be adjusted to lower concentrations to meet the cumulative carcinogenic risk level and hazard index criteria specified in §350.72(c). For COCs which exhibit both carcinogenic and noncarcinogenic characteristics, they shall be evaluated as both a carcinogen and noncarcinogen when determining whether the PCL established for an individual COC for each of the individual and combined human health exposure pathways needs to be adjusted to a lower concentration to meet the cumulative risk and hazard criteria. The person shall then use the lower of the carcinogenic or noncarcinogenic PCL as the Tier 1 human health PCL. In other words, the Tier 1 PCLs provided in this table for an individual COC should not be used as the final Tier 1 human health PCL for any of the individual or combined exposure pathways in cases where there are more than 10 carcinogenic and/or more than 10 noncarcinogenic COCs within a source medium unless it can be demonstrated that further downward adjustment is not necessary to meet the cumulative risk and hazard criteria.","commercial/industrial land use, 30 acre source area"],"cite":{"instrument":"us_tx_trrp_pcl","title":"Texas Risk Reduction Program (30 TAC Chapter 350): Tier 1 protective concentration levels — Table 1 Residential Soil, Table 2 Commercial/Industrial Soil, Table 3 Groundwater (residential and commercial/industrial)","issuer":"Texas Commission on Environmental Quality (TCEQ)","edition":"TRRP Tier 1 PCL tables, Last Revised: February 6, 2025 (TCEQ, PDF version)","source_url":"https://www.tceq.texas.gov/downloads/remediation/trrp/2025-pcl-tables-6-february-2025-final.pdf","source_sha256":"fb90ae0c95044f80cf21c83087ddbdc18ceee259ef8a6531887cc5c454d67686","fetched_at":"2026-10-15","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"TRRP Table 3, Groundwater, AirGWInh-V 30 acre source area, Commercial/Industrial","page":39,"quote":"Benzidine 92-87-5 4.0E-06 I c 4.0E-04 I c 5.0E+00 I c 8.4E-01 c 8.9E-06 I c 8.9E-04 I c 8.4E+00 I c 1.4E+00 c ─"}},{"id":"83fff67d45b18fa2","parameter":"Benzidine","value":"0.0015","value_num":0.0015,"unit":"µg/L","direction":"max","kind":"guideline","medium":"surface_water","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["surface water designated or used for public drinking water supply, or a sole-source surface drinking water supply (30 TAC §307.6(d)(2)(A), Column A)"],"cite":{"instrument":"us_tx_wqs","title":"Texas Surface Water Quality Standards, 30 TAC Chapter 307 (2022): §307.6 Table 1 aquatic life (freshwater and saltwater acute/chronic) and Table 2 human health; §307.7 Table 3 dissolved oxygen","issuer":"State of Texas, Texas Commission on Environmental Quality (TCEQ)","edition":"2022 Texas Surface Water Quality Standards (Rule Project No. 2020-014-307-OW), effective June 27, 2025, as US EPA posts them (cover dated July 1, 2025) with what EPA has approved for CWA purposes","source_url":"https://www.epa.gov/system/files/documents/2023-12/txwqs-2022.pdf","source_sha256":"88ff93dcfb277feec248541b2aa9a0f01cd3a747cda6e03d958344ee4a34ce5e","fetched_at":"2026-10-14","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"30 TAC §307.6(d) Table 2","page":46,"quote":null}},{"id":"3e69101ffefcff3a","parameter":"Benzidine","value":"0.107","value_num":0.107,"unit":"µg/L","direction":"max","kind":"guideline","medium":"surface_water","level":"regional","parameter_key":"cas:92-87-5","place":["US-TX"],"conditions":["surface water with a sustainable fishery not designated or used for public water supply (30 TAC §307.6(d)(2)(B), Column B); in an incidental fishery the criterion is ten times this value (30 TAC §307.6(d)(6))"],"cite":{"instrument":"us_tx_wqs","title":"Texas Surface Water Quality Standards, 30 TAC Chapter 307 (2022): §307.6 Table 1 aquatic life (freshwater and saltwater acute/chronic) and Table 2 human health; §307.7 Table 3 dissolved oxygen","issuer":"State of Texas, Texas Commission on Environmental Quality (TCEQ)","edition":"2022 Texas Surface Water Quality Standards (Rule Project No. 2020-014-307-OW), effective June 27, 2025, as US EPA posts them (cover dated July 1, 2025) with what EPA has approved for CWA purposes","source_url":"https://www.epa.gov/system/files/documents/2023-12/txwqs-2022.pdf","source_sha256":"88ff93dcfb277feec248541b2aa9a0f01cd3a747cda6e03d958344ee4a34ce5e","fetched_at":"2026-10-14","source_status":{"checked":"2026-10-15","status":"not verified"},"section":"30 TAC §307.6(d) Table 2","page":46,"quote":null}},{"id":"eda4dc39079ecf13","parameter":"Benzidine","value":"0.00014","value_num":0.00014,"unit":"µg/L","direction":"max","kind":"guideline","medium":"surface_water","level":"national","parameter_key":"cas:92-87-5","place":["US"],"conditions":["EPA's recommendation under Clean Water Act § 304(a): 'State and Tribal governments may use these criteria or use them as guidance in developing their own' — it binds a water once the state adopts it for the water's designated use","receiving_water is freshwater","consumption of water + organism: a water designated a drinking-water source and for fish and shellfish (a designated use the state assigns)"],"cite":{"instrument":"us_nrwqc_human_health","title":"EPA National Recommended Water Quality Criteria — Human Health Criteria Table (water + organism, organism only)","issuer":"U.S. Environmental Protection Agency","edition":"EPA web table (fetched 2026-10-09); 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