We have identified a new Lyman limit absorption system towards PKS1937-1009 , with log N ( H i ) = 18.25 \pm 0.02 at z = 3.256 that is suitable for measuring D/H .
We find a 68.3 % confidence range for D/H of 1.6 ^ { +0.25 } _ { -0.30 } \times 10 ^ { -5 } , and a 95.4 % range of 1.6 ^ { +0.5 } _ { -0.4 } \times 10 ^ { -5 } .
The metallicity of the cloud where D/H was measured is low , [ Si/H ] = -2.0 \pm 0.5 .
At these metallicities we expect that D/H will be close to the primordial value .
Our D/H is lower than the D/H value predicted using the \Omega _ { b } calculated from the cosmic background radiation measured by WMAP , 2.60 ^ { +0.19 } _ { -0.17 } \times 10 ^ { -5 } .
Our result also exacerbates the scatter in D/H values around the mean primordial D/H .