来源：中国环境报

防控历史遗留涉金属矿(kuang)区污(wu)染风(feng)险，是持续深入(ru)打好污(wu)染防治攻坚战、推进美丽(li)中(zhong)国建设的(de)(de)一项重(zhong)要任务。历史遗留涉金属矿(kuang)区污(wu)染呈现区域性、流(liu)域性、多环境介质复合性的(de)(de)特点，对周(zhou)边的(de)(de)土(tu)壤、地(di)表(biao)水(shui)、河道(dao)底泥、地(di)下水(shui)等造成不同(tong)程度(du)的(de)(de)影(ying)响，当周(zhou)边分(fen)布有(you)耕地(di)和重(zhong)要水(shui)体时影(ying)响更加突出。

我(wo)国(guo)目前尚(shang)无涉(she)金属(shu)矿区(qu)污(wu)(wu)染(ran)(ran)(ran)源(yuan)(yuan)(yuan)污(wu)(wu)染(ran)(ran)(ran)排放(fang)控制(zhi)标(biao)准(zhun)，且因(yin)此类(lei)污(wu)(wu)染(ran)(ran)(ran)源(yuan)(yuan)(yuan)呈现(xian)(xian)面源(yuan)(yuan)(yuan)污(wu)(wu)染(ran)(ran)(ran)特(te)点，传统的(de)(de)(de)污(wu)(wu)染(ran)(ran)(ran)源(yuan)(yuan)(yuan)整治(zhi)(zhi)达(da)标(biao)排放(fang)思(si)路(lu)与(yu)(yu)历(li)史(shi)(shi)遗(yi)留(liu)矿区(qu)污(wu)(wu)染(ran)(ran)(ran)防治(zhi)(zhi)实践不够适(shi)配，为推进(jin)历(li)史(shi)(shi)遗(yi)留(liu)涉(she)金属(shu)矿区(qu)污(wu)(wu)染(ran)(ran)(ran)防治(zhi)(zhi)带来一(yi)些现(xian)(xian)实问题。特(te)征性污(wu)(wu)染(ran)(ran)(ran)指(zhi)标(biao)，包括铁、锰、锑、铊等，在(zai)(zai)地(di)(di)表(biao)水(shui)(shui)(shui)环(huan)(huan)(huan)境质量(liang)标(biao)准(zhun)的(de)(de)(de)分(fen)类(lei)标(biao)准(zhun)中没有(you)标(biao)准(zhun)值(zhi)，仅(jin)在(zai)(zai)集中式生活饮用水(shui)(shui)(shui)地(di)(di)表(biao)水(shui)(shui)(shui)源(yuan)(yuan)(yuan)地(di)(di)的(de)(de)(de)“表(biao)2”和(he)(he)“表(biao)3”中出现(xian)(xian)，造成(cheng)缺(que)少适(shi)用的(de)(de)(de)质量(liang)标(biao)准(zhun)；直接引用“表(biao)2”和(he)(he)“表(biao)3”又(you)造成(cheng)标(biao)准(zhun)控制(zhi)过(guo)严、技术与(yu)(yu)经(jing)济(ji)难(nan)以(yi)兼(jian)顾的(de)(de)(de)问题。历(li)史(shi)(shi)遗(yi)留(liu)矿山污(wu)(wu)染(ran)(ran)(ran)源(yuan)(yuan)(yuan)往往集中分(fen)布在(zai)(zai)我(wo)国(guo)重(zhong)要河(he)流(liu)(liu)的(de)(de)(de)三级(ji)、四级(ji)甚至(zhi)五(wu)级(ji)支(zhi)流(liu)(liu)部分(fen)河(he)段上，这些河(he)段或没有(you)明确(que)的(de)(de)(de)水(shui)(shui)(shui)环(huan)(huan)(huan)境功能(neng)控制(zhi)要求(qiu)，或与(yu)(yu)一(yi)级(ji)、二(er)级(ji)支(zhi)流(liu)(liu)有(you)着相同的(de)(de)(de)水(shui)(shui)(shui)环(huan)(huan)(huan)境功能(neng)控制(zhi)要求(qiu)，也造成(cheng)技术与(yu)(yu)经(jing)济(ji)难(nan)以(yi)兼(jian)顾的(de)(de)(de)问题。

历史遗留涉(she)金(jin)属矿(kuang)(kuang)区污染防治(zhi)总体(ti)属于政府(fu)事权，需(xu)要地方政府(fu)投入大(da)(da)量资金(jin)开展整治(zhi)，整治(zhi)任务(wu)重(zhong)，资金(jin)需(xu)求(qiu)(qiu)量大(da)(da)。为(wei)有效解决整治(zhi)需(xu)求(qiu)(qiu)和现实中资金(jin)与(yu)技(ji)术不足的矛盾，笔者(zhe)认为(wei)，历史遗留涉(she)金(jin)属矿(kuang)(kuang)区污染防治(zhi)应大(da)(da)力探索以(yi)风险防控为(wei)导向而非(fei)污染控制标准为(wei)导向的新道路，大(da)(da)力推动风险评估(gu)技(ji)术体(ti)系(xi)的建立(li)和完善。

具体而言(yan)，要建立(li)基(ji)于风(feng)险(xian)防(fang)控(kong)断(duan)面(mian)(mian)和质(zhi)(zhi)量(liang)(liang)(liang)控(kong)制(zhi)断(duan)面(mian)(mian)防(fang)控(kong)下的风(feng)险(xian)防(fang)控(kong)总体思路，即以质(zhi)(zhi)量(liang)(liang)(liang)保(bao)障(zhang)断(duan)面(mian)(mian)重金(jin)属特征(zheng)污染(ran)物全面(mian)(mian)稳定达标(biao)、切实降低风(feng)险(xian)防(fang)控(kong)断(duan)面(mian)(mian)和质(zhi)(zhi)量(liang)(liang)(liang)控(kong)制(zhi)断(duan)面(mian)(mian)重金(jin)属风(feng)险(xian)为根本目标(biao)，处理好矿区重金(jin)属污染(ran)风(feng)险(xian)防(fang)控(kong)断(duan)面(mian)(mian)、质(zhi)(zhi)量(liang)(liang)(liang)控(kong)制(zhi)断(duan)面(mian)(mian)、质(zhi)(zhi)量(liang)(liang)(liang)保(bao)障(zhang)断(duan)面(mian)(mian)等三(san)级（类(lei)）断(duan)面(mian)(mian)的关(guan)系。

风(feng)(feng)险(xian)(xian)(xian)防(fang)(fang)(fang)(fang)控区(qu)(qu)是指将重金属污染(ran)(ran)源(yuan)分(fen)布(bu)较为集中、重金属污染(ran)(ran)物浓度相对较高的(de)(de)(de)(de)区(qu)(qu)域以(yi)(yi)及结合河流(liu)(liu)(liu)沟道(dao)分(fen)布(bu)情况具有一定(ding)汇(hui)水(shui)面(mian)(mian)积(ji)的(de)(de)(de)(de)范围划(hua)定(ding)出的(de)(de)(de)(de)特定(ding)区(qu)(qu)域。风(feng)(feng)险(xian)(xian)(xian)防(fang)(fang)(fang)(fang)控区(qu)(qu)内(nei)将重金属污染(ran)(ran)源(yuan)分(fen)布(bu)更加集中、呈现小(xiao)流(liu)(liu)(liu)域污染(ran)(ran)特征的(de)(de)(de)(de)小(xiao)区(qu)(qu)域划(hua)定(ding)为风(feng)(feng)险(xian)(xian)(xian)防(fang)(fang)(fang)(fang)控单元(yuan)(yuan)。若(ruo)干(gan)风(feng)(feng)险(xian)(xian)(xian)防(fang)(fang)(fang)(fang)控单元(yuan)(yuan)共同构(gou)成(cheng)一个风(feng)(feng)险(xian)(xian)(xian)防(fang)(fang)(fang)(fang)控区(qu)(qu)。风(feng)(feng)险(xian)(xian)(xian)管(guan)控断(duan)(duan)(duan)(duan)面(mian)(mian)是指风(feng)(feng)险(xian)(xian)(xian)防(fang)(fang)(fang)(fang)控区(qu)(qu)范围内(nei)，污染(ran)(ran)源(yuan)（矿硐(dong)、废渣(zha)、尾矿库等）分(fen)布(bu)较为集中区(qu)(qu)域的(de)(de)(de)(de)下游支(zhi)沟或河流(liu)(liu)(liu)在汇(hui)入上一级河流(liu)(liu)(liu)前(qian)一定(ding)距离（如50米—200米）的(de)(de)(de)(de)断(duan)(duan)(duan)(duan)面(mian)(mian)。当汇(hui)入点处存在一定(ding)数量(liang)的(de)(de)(de)(de)污染(ran)(ran)源(yuan)时，则将风(feng)(feng)险(xian)(xian)(xian)控制(zhi)(zhi)断(duan)(duan)(duan)(duan)面(mian)(mian)位置调整到汇(hui)入上一级河流(liu)(liu)(liu)后一定(ding)距离的(de)(de)(de)(de)断(duan)(duan)(duan)(duan)面(mian)(mian)。质(zhi)量(liang)控制(zhi)(zhi)断(duan)(duan)(duan)(duan)面(mian)(mian)是指风(feng)(feng)险(xian)(xian)(xian)防(fang)(fang)(fang)(fang)控区(qu)(qu)内(nei)主要河流(liu)(liu)(liu)流(liu)(liu)(liu)出风(feng)(feng)险(xian)(xian)(xian)防(fang)(fang)(fang)(fang)控区(qu)(qu)边(bian)界的(de)(de)(de)(de)断(duan)(duan)(duan)(duan)面(mian)(mian)。若(ruo)防(fang)(fang)(fang)(fang)控区(qu)(qu)内(nei)有一条以(yi)(yi)上的(de)(de)(de)(de)河流(liu)(liu)(liu)流(liu)(liu)(liu)出防(fang)(fang)(fang)(fang)控区(qu)(qu)，则将该防(fang)(fang)(fang)(fang)控区(qu)(qu)每(mei)条流(liu)(liu)(liu)出区(qu)(qu)域边(bian)界的(de)(de)(de)(de)断(duan)(duan)(duan)(duan)面(mian)(mian)均作(zuo)为质(zhi)量(liang)控制(zhi)(zhi)断(duan)(duan)(duan)(duan)面(mian)(mian)。

风险管(guan)(guan)控(kong)断面(mian)重(zhong)(zhong)金(jin)(jin)属(shu)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu)(wu)浓度与污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)源(yuan)关联性(xing)较大(da)，一旦污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)源(yuan)采取一定(ding)(ding)整治工(gong)程措(cuo)施(shi)后，断面(mian)特(te)征污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu)(wu)的(de)浓度可随之下(xia)降(jiang)。风险防控(kong)思路下(xia)，风险管(guan)(guan)控(kong)断面(mian)不以重(zhong)(zhong)金(jin)(jin)属(shu)特(te)征污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu)(wu)浓度达到某一地表水水质标(biao)(biao)准为要求(qiu)(qiu)，而是以污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu)(wu)浓度持续下(xia)降(jiang)、“磺(huang)水”等感官指标(biao)(biao)的(de)污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)流程不断缩短作为目(mu)标(biao)(biao)要求(qiu)(qiu)。此断面(mian)的(de)目(mu)标(biao)(biao)要求(qiu)(qiu)一方面(mian)直接(jie)指示了污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)源(yuan)工(gong)程治理的(de)成效，另一方面(mian)也(ye)保障了下(xia)游质量控(kong)制断面(mian)重(zhong)(zhong)金(jin)(jin)属(shu)特(te)征污(wu)(wu)(wu)(wu)染(ran)(ran)(ran)物(wu)(wu)(wu)达到预定(ding)(ding)目(mu)标(biao)(biao)。

在风险(xian)防(fang)控(kong)(kong)(kong)的(de)思路下，质量(liang)控(kong)(kong)(kong)制断面(mian)重(zhong)金(jin)属特征(zheng)污染物浓度(du)控(kong)(kong)(kong)制目标(biao)(biao)应以保证下游市控(kong)(kong)(kong)、省控(kong)(kong)(kong)和国控(kong)(kong)(kong)等质量(liang)保障断面(mian)达(da)(da)到相应水(shui)(shui)质要求(qiu)为目标(biao)(biao)，并按照一定技术方法进行计算，统筹计算结果(guo)和水(shui)(shui)质控(kong)(kong)(kong)制要求(qiu)综合(he)确(que)定，避(bi)免简单(dan)照搬水(shui)(shui)环境质量(liang)标(biao)(biao)准，避(bi)免简单(dan)的(de)全流域水(shui)(shui)质均(jun)要求(qiu)达(da)(da)到地表水(shui)(shui)环境质量(liang)标(biao)(biao)准的(de)“一刀(dao)切”问题。

笔者建(jian)议(yi)，在风(feng)险防(fang)控(kong)(kong)(kong)思路指(zhi)导下，还需要加快建(jian)立历史(shi)遗留涉金属(shu)(shu)矿区(qu)(qu)重金属(shu)(shu)污染风(feng)险评(ping)估技(ji)术(shu)体(ti)系。这一技(ji)术(shu)体(ti)系应包括风(feng)险防(fang)控(kong)(kong)(kong)区(qu)(qu)域划定技(ji)术(shu)、风(feng)险防(fang)控(kong)(kong)(kong)区(qu)(qu)域风(feng)险等(deng)级评(ping)价技(ji)术(shu)、质量控(kong)(kong)(kong)制断(duan)面(mian)特征污染物(wu)浓度控(kong)(kong)(kong)制值计算技(ji)术(shu)、区(qu)(qu)域涉金属(shu)(shu)矿山风(feng)险防(fang)控(kong)(kong)(kong)成效评(ping)价技(ji)术(shu)四个(ge)方(fang)面(mian)。

风(feng)险(xian)防(fang)(fang)(fang)控(kong)(kong)区(qu)域(yu)是治(zhi)理区(qu)制定(ding)目标(biao)(biao)、任务和实(shi)施工程的(de)主要(yao)对象，划定(ding)技术(shu)(shu)需要(yao)重点确(que)定(ding)风(feng)险(xian)防(fang)(fang)(fang)控(kong)(kong)区(qu)域(yu)边界与质(zhi)量(liang)(liang)控(kong)(kong)制断(duan)(duan)(duan)面(mian)的(de)划定(ding)统筹设计(ji)。风(feng)险(xian)防(fang)(fang)(fang)控(kong)(kong)区(qu)环境风(feng)险(xian)等级评(ping)价中(zhong)，需要(yao)基于根本保(bao)护目标(biao)(biao)（如质(zhi)量(liang)(liang)保(bao)障断(duan)(duan)(duan)面(mian)重金(jin)属(shu)污(wu)染(ran)(ran)物(wu)浓(nong)度(du)达到某一特(te)(te)定(ding)目标(biao)(biao)），构(gou)建基于“特(te)(te)定(ding)流(liu)域(yu)范(fan)围—风(feng)险(xian)防(fang)(fang)(fang)控(kong)(kong)区(qu)域(yu)—风(feng)险(xian)防(fang)(fang)(fang)控(kong)(kong)单元(yuan)”的(de)风(feng)险(xian)评(ping)估方法体系。质(zhi)量(liang)(liang)控(kong)(kong)制断(duan)(duan)(duan)面(mian)重金(jin)属(shu)特(te)(te)征污(wu)染(ran)(ran)物(wu)浓(nong)度(du)计(ji)算时需要(yao)建立风(feng)险(xian)防(fang)(fang)(fang)控(kong)(kong)区(qu)重金(jin)属(shu)特(te)(te)征污(wu)染(ran)(ran)物(wu)污(wu)染(ran)(ran)输入(ru)输出水质(zhi)影响(xiang)分析模型，科学确(que)定(ding)各(ge)风(feng)险(xian)防(fang)(fang)(fang)控(kong)(kong)区(qu)质(zhi)量(liang)(liang)控(kong)(kong)制断(duan)(duan)(duan)面(mian)特(te)(te)征污(wu)染(ran)(ran)物(wu)防(fang)(fang)(fang)控(kong)(kong)目标(biao)(biao)。区(qu)域(yu)涉金(jin)属(shu)矿山风(feng)险(xian)防(fang)(fang)(fang)控(kong)(kong)成效评(ping)价技术(shu)(shu)需要(yao)在区(qu)域(yu)水质(zhi)监测网(wang)络体系构(gou)建前提下，基于监测网(wang)络获得的(de)数据(ju)进行重金(jin)属(shu)污(wu)染(ran)(ran)浓(nong)度(du)改善、风(feng)险(xian)降低和稳定(ding)达标(biao)(biao)的(de)综(zong)合评(ping)价。

当前，我国涉金属矿山污染防治风险(xian)评估(gu)技术方(fang)法(fa)的规范(fan)性文件，包括行业标准、地方(fang)标准和(he)(he)团体标准等(deng)不同(tong)类型标准等(deng)，仍然(ran)比较缺乏，需要加快(kuai)研究和(he)(he)出台(tai)，以全面推动和(he)(he)规范(fan)历史遗留矿(kuang)山的环境风险(xian)评估(gu)。

作者：孙宁(ning)、张黎(li)明、张宗(zong)文、乔雄彪，生态环(huan)(huan)境部环(huan)(huan)境规划院生态环(huan)(huan)境工程(cheng)咨询中心