HHeadroomLower tier COMAH site
Right now

2 tank pairs are too close

Lower tier COMAH site · 1 to keep an eye on

Check a deliveryWhat can I take
Highest threshold use93%Across all three COMAH aggregation groups
Tank pairs too close2Separation rules breached
Inventory held3,712 t62% of 6,030 t capacity
Substances blocked0All substances have remaining headroom
COMAH threshold utilisationLower tier COMAH site

Closest COMAH limit

Lower tier COMAH site
Environmental hazards (Section E)93%
Mostly Sodium hypochlorite solution 14% (48% of the limit on its own)

Close enough that a large delivery could cross the threshold. Run an intake check before accepting.

Other 2 categories
Physical hazards (Section P + O)85%
Mostly Ammonia, anhydrous
Health hazards (Section H)49%
Mostly Ammonia, anhydrous

COMAH 2015 Sch. 1 Pt. 3, Note 4 — summation rule

What you can take today

All substances
  • Gas oil (distillate marine diesel)752.7 t
  • Toluene752.7 t
  • Methanol745 t
  • Sodium hypochlorite solution 14%37 t
  • Dibenzoyl peroxide paste (Type C)29.8 t

Tanks stored too close together

2 to fix
  • Fix

    Acrylonitrile DS-401 is in the same zone as Hydrogen peroxide 60% DS-401

    These two cannot share a zone. Move one to another tank.

    Why this rule applies
    Oxidising liquids/solids separated from flammable liquidsSEG-01

    Both substances are held in DS-401 with no internal separation. An oxidiser release into a flammable liquid pool supplies oxygen to the fire, defeating foam and vapour suppression.

    Measured
    same zone
    Required
    5 m or separate compartment

    HSG71 §Segregation of incompatible materials, Table 2; CLP Annex I classes 2.13 / 2.6

  • Fix

    Sodium hypochlorite solution 14% TK-201 is 6 m from Nitric acid 68% TK-202

    4 m short of the 10 m needed or put in a separate compartment.

    Why — 2 rules apply
    Active-chlorine releasing substances separated from acidsSEG-05Strictest

    TK-201 and TK-202 are 6 m apart with independent bunding between them. Mixing hypochlorite with acid liberates chlorine gas immediately and in quantity; a shared bund is a mixing path, not a barrier.

    Measured
    6 m · independent bunding
    Required
    10 m or separate compartment

    HSG71 §Segregation of incompatible materials, Table 2; HSG95 §Hypochlorite storage

    Corrosive acids separated from corrosive alkalisSEG-06

    TK-201 and TK-202 are 6 m apart with independent bunding between them. Neutralisation is violent and exothermic at bulk scale, with aerosol generation and containment damage.

    Measured
    6 m · independent bunding
    Required
    10 m or separate compartment

    HSG71 §Segregation of incompatible materials, Table 2

  • Watch

    Nitric acid 68% TK-202 is 11 m from Ammonia, anhydrous VS-302

    Meets the 10 m minimum, but only by 1 m. No room to move stock closer.

    Why this rule applies
    Corrosive acids separated from corrosive alkalisSEG-06

    TK-202 and VS-302 are 11 m apart with open ground between them. Neutralisation is violent and exothermic at bulk scale, with aerosol generation and containment damage.

    Measured
    11 m · open ground
    Required
    10 m or separate compartment

    HSG71 §Segregation of incompatible materials, Table 2

Northgate Bulk Storage Ltd · inventory as of 05 Aug 2026 · 10 zones · 3,712 t held against 6,030 t capacity