VERSITET SOIL CONTAMINATTION APRIL 2014 UNI INDOOR CLIMATE RISK ASSESSMENT

PEDER MARIBO APRIL RETARDATION AND GW FLOW Source Xylene Benzene MTBE Xylene: Koc = 200. R = 3.16 Benzene Koc = 50R = 1.54 MTBE Koc = 0.02R = 1.00 Regarding assignment 6 C: OBS, pollution transport velocity is V p V p = V/n (V = -K·dh/dx)

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL Xylene plume Benzene plume Conceptual models

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL SOIL GAS & INDOOR CLIMATE › Diffusion through porous layers (soil, concrete..) › Convection in cracks & macropores. Radon or Soil contamination (mineral oil (BTEX), chlorinated subst.)

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL Indoor climate (criteria) Substances in the soil environment WATER (dissolved) PARTICLES (sorbed) KdKd KHKH AIR

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL Danish EPA guideline no7, 2002, Remediation of contaminated sites, Diffusion: Ficks law

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL Danish EPA guideline no7, 2002, Remediation of contaminated sites, Diffusion through multiple layers:

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL Transport (2): Convective contribution (in cracks, - cf. “Qubics Law”)

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL Where: J: Flux [mg/m 2 ·s] W: crack width [m] (depending on reinforceement, concreet type, age…) C u : concentration under the floor l: floor thickness η : dynamic viscosity – gas [kg/(m·s)] A: area [m 2 ] ∆P: pressure difference over the floor [Pa] Calculation of convective indoor climate contribution (through cracks)

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL Where: C i : Indoor climate contribution (diffusion) J: flux of matter (diffusion + convection) L h : Room height in building [m] L s : Air exchange rate in room [S -1 ] Calculation of indoor climate contribution

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL RISK ASSESSMENT DK-EPA recommended procedure: 1)Calculate indoor air and air concentration below the building. Is C i below criteria? C UF below 100 x criteria? 2)Measure under-floor conc. Is it below 100 x critera? 3)Based on measured value in 2 calculate indoor concentration 4)Measure indoor concentration

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL › ADT/AC tube › OBS: Room ventilation Season GW level Wind & temp. Atm. pressure Available porespace Measurement of contribution

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL RISK ASSESSMENT USING THE JAGG MODEL (DANISH EPA) Groundwater Indoor climate Outdoor air quality

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL › (No free NAPL phase) › Phase equilibrium – stationary conditions › Ideal gas and water solutes (no interactions) › Sorption only to organic matter (K d = K oc ·f oc ) Particle sorbed ↔ water dissolved ↔ gas phase K d K H JAGG ASSUMPTIONS:

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL JAGG - INPUT DATA Default chemical data and standard soil data in JAGG. C.f. the DEPA guidelines 7/2002 – appendix 5.5 (DK: MST vejl 6/1998) n= V a + V w (= 0.35 – 0.5)Porosity. JAGG standards d2.6 – 2.7 kg/LParticle density ρbρb 1.4 – 1.7 kg/LSoil dry density ( ρ b = d·(1-n)) f oc 10 % % (K oc !)Model sensitivity P,S25 oC values(“conservative”)

INDOOR CLIMATE RISK ASSESSMENT PEDER MARIBO APRIL THE FLOOR Concrete floor: › Crack width w – important. Model is sensitive. › ∆P : natural vent: Pa. Mech vent: Pa. › N: depend much on concrete type – 5·10 -5 › X: Floor thickness › L s : air exchange rate. Typical 0.3 h -1 (institutions 2 h -1 ) Non concrete floor?