Correcting grammatical errors versus content in post-graduate coursework submissions in the sciences During an intramural teaching forum, I was interested to learn from a Head of Department (HoD) that she didn't consider it her role to correct grammatical errors when evaluating coursework submissions (an essay, say) at the post-graduate level and that she limited her assessments to the content of the essay. I'm an HoD myself and am directly opposed to this, and have strongly recommended to academic staff in my department that the assessment of grammar should be part of the feedback provided to students. My reasons for this are:


Communications with peers, the public and policy makers are important aspects of the role.
While a number of our students are non-native English language speakers, there are a number of so-called native English language speakers with atrocious writing skills.
The students appreciate the feedback they receive and we can detect a substantial improvement in their writing skills.


The other HoD's reasons are equally cogent:


The university already has a minimum language level required for entry.
This additional task would impose a heavy burden on her already limited staffing resources.
Students need only be made aware that there are errors and can seek guidance on correcting the grammatical issues elsewhere.


This is my question to you good folks:


  
  For teachers, what is the practice in your department and is this practice backed by specific assessment policies?
  For students, what are your expectations about your grammar being corrected?
  


EDIT: I am interested in approaches from STEM fields, primarily. As @DanRomik points out in the comments, the approach in the humanities and arts may be different.

To put this in perspective, here is part of a report submitted in partial fulfillment of a basic statistics course at the Master's level that I am grading at the moment. The statistical formulae, graphs and numerical results are spot on.


  This report uses te data from the study of [redacted] about lizard to do some analysis. Graph 1 shows the survival status of lizard. The value of survival lizard are higher than that of the death lizard.


How would you approach such a submission?

Thank you for your patience.

PS. I have found the related thread here but it focused on peer-review. Nevertheless, I accept that some grammatical errors are so egregious as to make the submission unintelligible. I am not concerned about those submissions here.
I am somewhere in between physics and mathematics. My personal policy is this:


I mark any spelling, punctuation, or grammar mistake I find, but I do not explicitly search for them. However, I usually do not go at lengths to explain why something is wrong.
This does not affect the grade unless the number of mistakes severely affects the readability of the text or is particularly egregious. (Being in Germany, I may be more lenient on submissions in German by non-native speakers, depending on the programme’s main language and other factors.)


My rationale for this is:


As I have to thoroughly read the text anyway, the additional effort for marking mistakes are negligible in comparison to the reading time. In most of the cases, it’s adding a comma, crossing out a letter, or replacing a single word. This applies to analogue submissions as well as to digital ones.
Just telling students that they made language mistakes somewhere in their writings does not really help them. The effort of seeking help from a third party is unfeasible in most situations (and disproportionate in comparison to my effort). However, I expect that they are able to find out the source of a specific mistake that I marked.
The admission requirements should not and cannot be so strict that only people who completely mastered the language can be admitted. In many languages, even native speakers tend to commit some systematic spelling mistakes (in particular regarding punctuation) that can only be weeded out this way.


So in short, I think that the other HoD’s rationale is blatantly misjudging factors.

We do not have any departmental policies regarding this here, but I know many that follow a similar policy.