Small-Scale Sand Filter¶

Small-scale sand filters are governed by BMP Manual Chapter 9.9 in the live source corpus. This page stays with the source-backed fundamentals: compact sand-media filtration, infiltrating GI configuration, and the difference between this chapter's infiltrating type and the underdrained type (Chapter 11.4), which is explicitly excluded from Chapter 9.9.

Structured citation evidence for this page lives in the sibling claim manifest.

Overview¶

In the enrolled source set, Chapter 9.9 covers the infiltrating configuration of the small-scale sand filter — a compact filtration BMP that routes runoff through a sand-media system and into the subsoil. The underdrained type does not meet the definition of green infrastructure and is explicitly excluded from Chapter 9.9; it belongs to Chapter 11.4 (Sand Filters with Underdrain), which is not enrolled in this family.

Source Mapping¶

The live citations layer resolves this route directly to the following canonical source bundles.

Route type: canonical
2023 source bundle: Chapter 9.9 (2023_BMP_9_9) - Small-Scale Sand Filters
2026 source bundle: Chapter 9.9 (2026_BMP_9_9) - Small-Scale Sand Filters

Key verified claims already tied to this page manifest: - Chapter 9.9 covers compact sand-media filtration rather than native-soil infiltration. - Chapter 9.9 covers the infiltrating GI type; the underdrained type is excluded from this chapter and belongs to Chapter 11.4. - Pretreatment remains critical to small-scale sand-filter performance.

Design Criteria¶

The reconciled design criteria below come from the live crosswalk and page-level claim set, not from the older narrative snapshot.

This route does not have a dedicated parameter table in the crosswalk, so the controlling criteria stay tied to the verified claims and canonical source-bundle mapping below.

Source-backed criteria that still control this route: - Chapter 9.9 covers compact sand-media filtration rather than native-soil infiltration. - Chapter 9.9 covers the infiltrating GI type; the underdrained type is excluded from this chapter and belongs to Chapter 11.4. - Pretreatment remains critical to small-scale sand-filter performance.

Siting Constraints¶

The current source-backed siting review should focus on:

whether the project needs compact infiltrating filtration rather than an underdrained configuration
whether the subsoil can support infiltration (native-soil permeability requirements apply)
whether the layout provides access, pretreatment, and overflow routing compatible with the chapter

Maintenance¶

Maintenance stays tied to filter performance:

preserve pretreatment so fine sediment does not blind the sand surface
monitor drainage through the observation and access features
treat sand replacement and clogging as core lifecycle issues

Source Bundles¶

Use these source bundles when checking the live extracted text or paired OCR evidence:

2023 bundle: Chapter 9.9 (2023_BMP_9_9) - Small-Scale Sand Filters
2026 bundle: Chapter 9.9 (2026_BMP_9_9) - Small-Scale Sand Filters