Dear Leela,

I think you already had good feedback from the community. Just another thought. I am not aware of your study area, orography, groundwater exchange, etc. However, I wonder if there are heavy rainfall events in the area. Depending on the moisture sources and recharge turnover, this can affect to the specific MWLs.  If this topic is of interest to you, I suggest to have a look at Li et al (2018): Groundwater Isotopes Biased Toward Heavy Rainfall Events and Implications on the Local Meteoric Water Line.

Best wishes

David X. Soto, Ph.D.
Department of Earth and Environmental Sciences
KU Leuven
Celestijnenlaan 200E
3001 Leuven, Belgium
Email: [log in to unmask]

On Sun, Sep 15, 2019 at 4:56 PM Leela <[log in to unmask]> wrote:
I measured several ground water samples from a temperate region (Lat 42 deg). The hydrogen vs oxygen gives a slope of 3.5 and an intercept of -5. I can understand such a behavior from an arid region. Many samples from an nearby filed gave a slope of 7.7 and intercept of 11. Any suggestions