北京市大兴区二次供水卫生管理安全现状

目的为了解北京市大兴区二次供水安全管理现状,建立一套全面完整的二次供水资料,为应对饮用水突发事件做相应的准备工作。方法于2009—2010年对辖区内正常供水的二次供水单位进行调查,采集水箱处理后的水样进行检测,按照《二次供水设施卫生规范》(GB 17051-1997)、《生活饮用水水质卫生规范》(2001)和《生活饮用水卫生标准》(GB5749-2006)进行评价。结果共调查二次供水单位71家,二次供水设施78个,水箱82个,供水人口83 884人。二次供水处理后水样合格率为80.8%。不合格项目为总硬度、硝酸盐氮和细菌总数,超标率分别为7.7%,6.5%,5.1%。其余项目均合格。以市政供水为水源的二次供水合格率为93.8%,高于自备井水的合格率(15.4%),差异有统计学意义(P0.01)。以市政供水为水源的二次供水不合格项是细菌总数,自备水水源的不合格项是总硬度和硝酸盐氮。经低位水箱加变频泵处理的二次供水水样合格率为84.2%(48/57),高于经无负压直供水处理的二次供水水样[66.6%(6/9)],但经比较差异无统计学意义(P0.05)。采用紫外线消毒、水箱自洁器消毒、氯化消毒、臭氧消毒的二次供水水样细菌总数合格率分别为94.9%(56/59)、88.9%(8/9)、100.0%(2/2)、100.0%(2/2),四者间差异无统计学意义(P0.05)。结论该区二次供水单位卫生管理不到位,二次供水设施水箱设计存在安全隐患,今后应加强二次供水的卫生监管工作。

Present situation of health management of secondary water supply in Daxing district of Beijing

[Objective]To understand the present situation of safety management of secondary water supply in Daxing district of Beijing,establish a complete set of data for secondary water supply,and carry out the relevant preparation work for dealing with the drinking water emergent events.[Methods]The secondary water plants which ran normally in Daxing district were investigated during 2009-2010,and the water samples were collected and tested.The evaluation was conducted according to the Hygienic specification for facilities of secondary water supply(GB 17051-1997),the Sanitation criterion for drinking water quality(2001) and the Drinking water sanitary standard(GB 5749-2006).[Results]The investigation included 71 secondary water plants,78 secondary water supply facilities and 80 water tanks,which involved 83 884 people.The qualified rate of treated water samples of secondary water supply was 80.8%.The major unqualified items were total hardness,nitrate nitrogen and total bacterial count,which the over standard rate was 7.7%,6.5% and 5.1% respectively.And the rest items were qualified.The qualified rate of secondary water supply which the water sources were municipal water supply(93.8%) was higher than that of well water(15.4%) significantly(P<0.01).The unqualified item of municipal water supply was total bacterial count,and the unqualified items of self-prepared water supply were total hardness and nitrate nitrogen.The qualified rate of water samples treated by lower punch water tanks and variable frequency pumps was 84.2%(48/57),which was higher than that by non-negative pressure direct water supply [66.6%(6/9)],and the difference was not significant(P>0.05).The qualified rate of total bacterial count of water samples treated by ultraviolet disinfection,self-cleaning disinfection,chlorination and ozone disinfection was 94.9%(56/59),88.9%(8/9),100.0%(2/2) and 100.0%(2/2)respectively,and the difference among them was not significant(P>0.05).[Conclusion]The health management of secondary water supply in Daxing district is not good,and there is hidden danger in tank design of secondary water supply facilities.The hygiene supervision of secondary water supply should be strengthened in future.