Field Service Report · Remediation
FSR-2090-0466 — Sky-Garden Spore Bloom Remediation
Suppression of a toxic spore bloom on a GCL-2 rooftop sky-garden specimen (UF-27710) at Helix Tower. Non-zero VOC/Toxin Index readings required respiratory PPE; partial suppression achieved on-site with scheduled follow-up monitoring (outcome MONITORED).
Engagement classification. GCL-2 toxic remediation with active aerial spore release. Respiratory PPE (P3 + sealed eye protection) and two-person rule mandatory. Exposure first-response staged per VC-SOP-0307; spore waste handled per VC-SOP-0318. Full eradication not achievable in one visit — monitored disposition.
1. Site & Conditions
| Field | Entry |
|---|---|
| Site name / client | Helix Tower Sky-Garden (Tier-1 managed rooftop installation) |
| Location / access | 41st-floor terrace garden; access via secured roof lobby. Exposed, breezy — downwind drift risk. |
| Engagement type | Remediation (toxic) |
| Ambient temp / RH | 14 °C / 77 %RH; wind 18 km/h gusting — favored sporulation and drift |
| Conditions on arrival | Visible powdery spore mass on the specimen's lower canopy; faint aerosol haze; two adjacent ornamentals showing early colonization. |
| Public proximity | Terrace closed; 6 m downwind cordon set; HVAC intake for the floor isolated by building staff. |
2. Specimen Identification
| Field | Entry |
|---|---|
| Common name | Ashveil Fern (engineered alkaloid-spore cultivar) |
| Cultivar / accession | UF-27710 — managed installation specimen, GreenWorld-placed |
| Assessed GCL grade | GCL-2 (respiratory-irritant toxic spore; aerial dispersal under wind; no predation) |
| Approx. size | ~1.3 m fern in raised bed; ~0.4 m² affected lower-canopy area |
| Observed hazards | Active sporulation; airborne alkaloid load; VOC/Toxin Index elevated (see §4) |
| Provenance | Confirmed — installation accession UF-27710; spore type matched via PhytoSense swab |
3. Work Performed
- Established 6 m downwind cordon; confirmed floor HVAC intake isolated. Briefed roles: Aralia handler, Sorrel exposure-watch with first-response kit per VC-SOP-0307.
- Donned P3 respirators, sealed eye protection, field-grade suits, and dosimeters. Confirmed PhytoSense handset and aerosol sampler calibration (cal age 3 d).
- Captured arrival readings (Section 4); aerosol sampler logged airborne Toxin Index in the work zone.
- Applied a wetting fixative spray to the spore mass to suppress further aerosolization before any contact (knock-down before cut).
- Excised the heavily colonized lower-canopy fronds; bagged directly into sealed spore-waste sleeves per VC-SOP-0318.
- Treated the residual crown and two adjacent ornamentals with a sporostatic agent to arrest re-bloom; could not fully eradicate established mycelium in one pass.
- Damp-wiped terrace hardscape in the drift zone; sampled surfaces for settled spore load.
- Performed staged decon of suits, tools, and respirators; confirmed dosimeters clear; broke cordon. Set a 14-day monitoring return.
4. Readings Captured
| Metric | Unit | Nominal Band | Arrival | At Securing |
|---|---|---|---|---|
| Canopy Vitality Index | % | ≥ 90 | 88.0 | 84.2 (post-excision) |
| VOC / Toxin Index (work zone air) | ppb | < OEL (90) | 148 | 52 |
| Spore Density (aerosol sampler) | cfu/m³ | < 50 | 1,920 | 310 |
| Surface Spore Load (drift zone) | cfu/cm² | < 5 | 62 | 7 |
| Substrate pH | — | 5.8–6.2 | 6.0 | 6.0 |
| Personnel Dosimeter | — | clear | clear | clear |
Air Toxin Index52 ppb▼ from 148 (OEL 90)
Aerosol Spore Density310▼ 84% on-site
SuppressionPartialre-bloom risk
On-Site Time2.8 htoxic band
5. Parts & Consumables
| Item | Part / Lot | Qty | Notes |
|---|---|---|---|
| Wetting fixative (spore knock-down) | SPR-FIX-09 | 0.8 L | Applied before excision |
| Sporostatic treatment agent | SPR-STAT-14 | 0.5 L | Crown + adjacent ornamentals |
| Spore-waste sealed sleeve | SW-LOT-1107 | 5 | Per VC-SOP-0318; incineration stream |
| P3 respirator cartridge pair | PPE-RSP-3 | 2 | Spent, disposed |
| Aerosol sampler media cassette | AS-MED-22 | 3 | Lab-submitted for spore typing |
6. Containment Actions
- PPE: P3 respirator, sealed eye protection, field-grade suit, dosimeter (GCL-2 toxic subset)
- Containment method: wetting knock-down + sealed spore-waste sleeves; sporostatic treatment
- Two-person rule observed: Yes — handler + exposure-watch with first-response kit
- Field dispersal control: downwind cordon, HVAC intake isolated, drift-zone surface wipe + sampling
- Exposure first-response: VC-SOP-0307 kit staged; no exposure event occurred
- Decon on egress: staged suit/tool/respirator decon; dosimeters clear
7. Outcome & Disposition
| Outcome | Monitored |
| Specimen disposition | Retained in place under suppression; established mycelium not fully eradicated. Spore waste incinerated per VC-SOP-0318. |
| Site left in condition | Air Toxin Index and aerosol density reduced below action thresholds; re-bloom risk remains — monitoring return scheduled. |
| Emergency procedure triggered? | No — controlled toxic remediation; no exposure, no breach. |
| On-site duration | 2.8 h (within 3.0 h toxic-dispatch target) |
8. Follow-Up Actions
- 14-day monitoring return — air/aerosol re-sample + re-treat if re-bloom — owner: S. Aralia — due 2090-02-25.
- Lab spore-typing of sampler cassettes to confirm cultivar and resistance — owner: Phyto-Synthesis Bay — due 2090-02-18. Done
- Evaluate specimen for relocation to GCL-2 vault if re-bloom recurs at +14 d — owner: D. Hemlock — due 2090-02-25.
9. Lessons Learned
Lesson — knock-down before cut, and never single-pass an established spore bloom. The wetting fixative cut aerosol spore density before any tissue was disturbed, holding the work-zone Toxin Index manageable; excising fronds dry would have spiked airborne load. One visit suppressed but did not eradicate established mycelium, so a monitored disposition with a 14-day return is the correct outcome — recording it as RESOLVED would have understated the re-bloom risk. Recommendation: codify wetting knock-down as a mandatory first step for any aerial-spore cultivar in VC-SOP-0512. Submitted to Dispatch Lead.
10. Signatures
| Role | Name | Date |
|---|---|---|
| Field Technician | S. Aralia | 2090-02-11 |
| Field Observer | J. Sorrel | 2090-02-11 |
| Dispatch Lead | S. Aralia | 2090-02-12 |
| Containment Officer | D. Hemlock | 2090-02-12 |