SY/T 7680-2023 in English

Analysis of the core content of the standard

Key technical points

1. Differentiated exploration strategy

The specification specifies three types of point distribution methods according to the characteristics of the pollution source: point pollution adopts radial distribution (spacing 10-20m), surface pollution adopts grid distribution (line spacing 10-20m), and line pollution adopts a combination of bilateral distribution modes.

2. Special requirements for soil sample collection

Remediation technology implementation suggestions

Vertical barrier technology selection

When the depth of contaminated groundwater is less than 30m, it is recommended to use a combined process of high-pressure jet grouting wall (permeability coefficient ≤1×10⁻⁷cm/s) and solidification stabilization. A case study of an oil field shows that this combination reduces the concentration of downstream benzene by 92%.

Monitoring well construction specifications

The porosity of the filter pipe must meet the requirements of D10 filter material ≥D90 formation, the thickness of the quartz sand filter layer must be ≥50mm, and the turbidity of the well washing must be <50NTU. The wellbore structure diagram provided in Appendix B clarifies key parameters such as the opening diameter and the location of the filter pipe.

Analysis of Standard Evolution

Compared with SY/T 6620-2014, this specification has the following major improvements:

1. Newly added differentiated detection requirements for petroleum hydrocarbons C6-C9/C10-C40
2. Introduction of quantitative standards for engineering geophysical exploration technology (such as the resistivity method profile length ≥ 6 times the detection depth)
3. Clearing the hierarchical relationship between risk control and restoration

Solutions to Common Problems

Q:How to avoid cross-contamination in multi-layer aquifers?
A:Article 5.2.6 of the specification requires the use of multi-stage casing for layered plugging, and the filter pipes of each layer shall not cross the layer, and the water-stopping material shall be filled to within 500mm of the ground.