Statutes, codes, and regulations
District Of Columbia Administrative Code
Title 12 - CONSTRUCTION CODES SUPPLEMENT OF 2017Subtitle 12-K - GREEN CONSTRUCTION CODE SUPPLEMENT OF 2017
Chapter 12-K4 - SITE DEVELOPMENT AND LAND USE
Rule 12-K405 - MANAGEMENT OF VEGETATION, SOILS, AND EROSION CONTROL

D.C. Mun. Regs. tit. 12, r. 12-K405

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Current through Register Vol. 71, No. 49, December 6, 2024
Rule 12-K405 - MANAGEMENT OF VEGETATION, SOILS, AND EROSION CONTROL

Strike Sections 405.1 and 405.1.1 of the International Green Construction Code in their entirety and insert new Sections 405.1 and 405.1.1 into the Green Construction Code in their place to read as follows:

405.1

Soil and water quality protection. Soil and water quality shall be protected in accordance with Sections 405.1.1 and .405.1.4.

405.1.1

Soil and water quality protection plan. A soil and water quality protection plan shall be submitted by the owner or the owner's authorized agent and approved prior to cons truction. The protection plan shall address the following:

1. A soils map, site plan, or grading plan that indicates designated soil management areas for all site soils, including, but not limited to:
1.1. Soils that will be retained in place and designated as vegetation and soil protection areas.
1.2. Topsoils that will be stockpiled for future reuse and the locations for the stockpiles.
1.3. Soils that will be disturbed during construction and plans to restore disturbed soils and underlying subsoils to soil reference conditions.
1.4. Soils that will be restored and re-vegetated.
1.5. Locations for all laydown and storage areas, parking areas, haul roads and construction vehicle access, temporary utilities and construction trailer locations.
1.6. Treatment details for each zone of soil that will be restored, including the type, source and expected volume of materials, including compost amendments, mulch and topsoil.
1.7. A narrative of the measures to be taken to ensure that areas not to be disturbed and areas of restored soils are protected from compaction by vehicle traffic or storage, erosion, and contamination until project completion.
2. A written periodic maintenance protocol for landscaping, including, but not limited to:
2.1. A schedule for periodic watering of new planting that reflects different water needs during the establishment phase of new plantings as well as after establishment. Where development of the building site changed the amount of water reaching the preserved natural resource areas, include appropriate measures for maintaining the natural areas.
2.2. A schedule for the use of fertilizers appropriate to the plants species, local climate and the pre-establishment and post-establishment needs of the installed landscaping. Nonorganic fertilizers shall be discontinued following plant establishment.

Strike Sections 405.1.2 and 405.1.3 of the International Green Construction Code in their entirety without substitution.

Strike Sections 405.1.4, 405.1.4.1 and 405.1.4.2 of the International Green Construction Code in their entirety and insert new Sections 405.1.4, 405.1.4.1 and 405.1.4.2 in their its place in the Green Construction Code to read as follows:

405.1.4

Soil reuse and restoration. Soils that are being placed or replaced on a building site shall be prepared, amended and placed in a manner that establishes or restores the ability of the soil to support the vegetation that has been protected and that will be planted. Soil reuse and restoration shall be in accordance with Sections 405.1.4.1 and 405.1.4.2.

405.1.4.1

Preparation. Before placing stockpiled or imported topsoils, compliance with all of the following shall occur:

1. Areas shall be cleared of debris including, but not limited to, building materials, plaster, paints, road base type materials, petroleum-based chemicals, and other harmful materials;
2. Areas of construction-compacted subsoil shall be scarified; and
3. The first lift of replaced soil shall be mixed into this scarification zone to improve the transition between the subsoil and overlying soil horizons.

Exceptions: Scarification is prohibited in all of the following locations:

1. Where scarification would damage existing tree roots.
2. On inaccessible slopes.
3. On or adjacent to trenching and drainage installations.
4. On areas intended by the design to be compacted such as abutments, footings, and inslopes.
5. Brownfields.
6. Other locations where scarification would damage existing structures, utilities and vegetation being preserved.
405.1.4.2

Restoration. Soils disturbed during construction shall be restored in areas that will not be covered by buildings, structures or hardscapes. Soil restoration shall comply with Items 1 and 2:

1.Organic matter. To provide appropriate organic matter for plant growth and for water storage and infiltration, soils shall be amended with a mature, stable compost material so that not less than the top 12 inches (305 mm) of soil contains not less than 3 percent organic matter. Sphagnum peat or organic amendments that contain sphagnum peat shall not be used. Soil organic matter shall be determined in accordance with ASTM D2974. Organic materials selected for onsite amendment or for blending of imported soils shall be renewable within a 50 -year cycle.

Exception: Where the reference soil for a building site has an organic level depth other than 12 inches (305 mm), soils shall be amended to organic matter levels and organic matter depth that are comparable to the site's reference soil.

2.Additional soil restoration criteria. In addition to compliance with Item 1 Organic Matter, soil restoration shall comply with not less than three of the following criteria:
2.1.Compaction. Bulk densities within the root zone shall not exceed the densities specified in Table 405.1.4 and shall be measured using a soil cone penetrometer in accordance with ASAE S313.3. The root zone shall be not less than 12 inches (305 mm), nor less than the site's reference soil, whichever results in the greater depth of measurement. Data derived from a soil cone penetrometer shall be reported in accordance with ASAE EP542.
2.2.Infiltration rates. Infiltration rates or saturated hydraulic conductivity of the restored soils shall be comparable to the site's reference soil. Infiltration rates shall be determined in accordance with AS TM D3385 or ASTM D5093. For sloped areas where the methods provided in the referenced standards cannot be used successfully, alternate methods approved by the code official shall be permitted provided that the same method is used to test both reference soil and onsite soil.
2.3.Soil biological function. Where remediated soils are used, the biological function of the soils' mineralizable nitrogen shall be permitted as a proxy assessment of biological activity.
2.4.Soil chemical characteristics. Soil chemical characteristics appropriate for plant growth shall be restored. The pH, cation exchange capacity and nutrient profiles of the original undisturbed soil or the site's reference soil shall be similar in restored soils. Salinity suitable for regionally appropriate vegetation shall be established. Soil amendments and fertilizers shall be selected from those which minimize nutrient loading to waterways or groundwater.

TABLE 405.1.4 MAXIMUM CONE PENETROMETER READINGS

SURFACE RESISTANCE (PSI)

SUBSURFACE RESISTANCE (PSI)

All

Textures

Sand

Sand

(includes loamy sand, sandy loam, sandy clay loam, and sandy clay)

Silt

(includes loam, silt loam, silty clay loam, and silty clay)

Clay (includes clay loam)

110

260

260

225

Strike Sections 405.1.5 and 405.1.6 of the International Green Construction Code in their entirety without substitution.

Strike Section 405.2 of the International Green Construction Code in its entirety and insert new Section 405.2 in the Green Construction Code in its place to read as follows:

405.2

Invasive plant species.Invasive plant species shall not be planted on a building site. Containment or removal of any invasive plant species currently on the site is required.

Strike Section 405.3 of the International Green Construction Code in its entirety and insert new Section 405.3 in the Green Construction Code in its place to read as follows:

405.3

Native plant landscaping. Where new landscaping is installed as part of a site plan or within the building site, not less than 50 percent of the newly landscaped area shall be planted with native plant species.

Exceptions:

1. Locations where non- native plant species are required by laws or regulations of the District of Columbia;
2. Vegetative roofs for buildings or structures; or
3. Trees.

D.C. Mun. Regs. tit. 12, r. 12-K405

Final Rulemaking published at 67 DCR 5679 (5/29/2020)