I took this subject as a science elective, and found it generally enjoyable. You will notice that the practical component is worth as much as the exam, so you should take the reports quite seriously. The pracs were quite easy and you are given the chance to use instruments for gas chromatography, HPLC and flame AAS which was nice after learning about them in Year 12 (Spas' section actually does devote a good amount of time in revising the background of these instruments as well as correct use of significant figures).
Lecturers: Spas and Trevor are both quite good lecturers and have good notes that are sufficient to understand what is needed for the exam. In general, the key areas covered involve the environmental chemistry of the lithosphere (eg. contaminants to the lithosphere), hydrosphere (contaminants to the hydrosphere) and atmosphere (eg. photochemistry in the atmosphere, stratification of the atmosphere etc.). If you do take this subject, be aware that the exam and general content aside from the group project is a MASSIVE MEMORY TEST. If you are comfortable with rote learning stuff, then you will find the exam very easy, however you may have to devote more time if you find it difficult to memorise things. Also, the "tutorials" for the class are utterly useless. Since the content is quite cut and dry in the sense that the answers are essentially just being able to recall facts, I would suggest simply printing off the tutorial questions provided, then working through them by yourself to test how much you can recall. If you cannot remember them, just look through the lecture notes!
Assessment: I've already mentioned the importance of the pracs and exam beforehand, so the other key assessment I will write on is the group project. This accounts for 20% of the total mark, and quite honestly, probably causes a lot of people to dismiss doing the subject due to the workload. Firstly, you work in groups of 3-4 people, and you are basically acting as a scientific consulting group to an Environmental Minister on an allocated environmental issue (for eg. my issue was whether electric cars should be introduced now/10 years in future/ 50 years in future/ never?). You have to take a collective stance among your team on the issue, and build up a report of about 8-10 pages with a focus on the environmental implications of the issue. All in all, I found that project very valuable as I built my teamwork/leadership skills and I actually learnt a lot from my other teammates (of whom, 2 of which were masters students). This report is typically due in the last week of semester, however you do have to do a short oral presentation to a portion of the class and one of the lecturers detailing your research and stance, however this does not account for any mark (it is only a hurdle requirement).
Recommendation: As I mentioned before, I found the subject enjoyable in the end because of the practical component and the group project which initially made me quite nervous given that there was a chance I could have been stuck with slackers for a semester. However, the rating I have given is above average only since the exam is a pure memory test. There is no variation in the questions that can be asked (ie. The question might simply ask for the name of a certain organic contaminant.), and this can make the content very dry. I suppose you would enjoy this subject if you want to get some experience in using HPLC, gas chromatography, UV/VIS spectroscopy, flame AAS etc., or want to learn the fundamentals of how environmental chemists view the hydrosphere, lithosphere and atmosphere.